Brain Tumor: Symptoms, Causes, Diagnosis and Treatment — What You Need to Know
Updated: 1 hour ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: September 2026
TL;DR: A brain tumor is any abnormal, uncontrolled growth of cells in the brain or the tissue around it. Noncancerous tumors grow slowly and often cause subtle symptoms that worsen over months or years; cancerous tumors cause symptoms that come on suddenly and worsen within days or weeks. Headaches are the most common symptom, occurring in about half of people with brain tumors. Only imaging tests and a biopsy can confirm a diagnosis and show whether a tumor is cancerous and how aggressive it is. Treatment is not always urgent: small, benign tumors without symptoms are often monitored with regular MRI scans, while cancerous or symptomatic tumors are treated with surgery, radiation, or medicines.
Quick Answer: What Is a Brain Tumor and How Is It Treated?
A brain tumor is a growth of cells in the brain that multiplies at an abnormal, uncontrollable rate. Tumors can be benign (noncancerous) or malignant (cancerous), and symptoms depend on the tumor's size, location, and growth rate. Headache, often worse in the morning, is the most common symptom. Diagnosis relies on imaging such as MRI and CT scans, plus a biopsy to determine type and grade. Treatment depends on whether the tumor is cancerous, its type, size, grade, and location, and may include surgery, radiation therapy, radiosurgery, chemotherapy, targeted therapy, or careful monitoring with regular MRI scans.
When Should You See a Doctor About Possible Brain Tumor Symptoms?
Make an appointment with your healthcare professional if you have persistent signs and symptoms that worry you. Persistent, worsening headaches (especially those that are worse in the morning, more frequent, more severe, or worse with coughing or straining) combined with new neurological changes such as vision problems, weakness in an arm or leg, balance trouble, speech problems, or a first-time seizure warrant prompt medical evaluation.
Persistent or worsening headaches, especially worse in the morning or with coughing or straining: make an appointment with your healthcare professional.
New vision changes, speech problems, balance trouble, or weakness in a limb: make an appointment promptly.
A first-time seizure (no history of seizures): seek urgent medical care.
Sudden confusion, severe headache with vomiting, or rapidly worsening symptoms: seek emergency medical care.
What Exactly Is a Brain Tumor?
A brain tumor is a growth of cells in the brain that multiplies at an abnormal, uncontrollable rate. The extra cells form a mass, or tumor, that can invade and destroy healthy tissue.
Not all brain tumors are cancer. Benign (noncancerous) brain tumors tend to cause symptoms that develop slowly, with subtle signs you might not notice at first. Malignant (cancerous) brain tumors, called brain cancers, cause symptoms that come on suddenly and worsen in a matter of days or weeks. Even a benign tumor can press on nerves, blood vessels, and surrounding tissue inside the rigid skull and cause damage, which is why all brain tumors deserve medical attention.
What Are the Symptoms of a Brain Tumor?
The signs and symptoms of a brain tumor depend on the tumor's size and location, as well as how fast it is growing, known as the tumor grade.
What Are the General Symptoms of a Brain Tumor?
Headache: pressure in the head that is worse in the morning; headaches that happen more often and seem more severe; headaches sometimes described as tension headaches or migraines.
Digestive: nausea or vomiting.
Vision and eyes: blurry vision, seeing double, or losing sight on the sides of your vision.
Movement and feeling: losing feeling or movement in an arm or a leg; trouble with balance.
Speech and thinking: speech problems; feeling very tired; confusion in everyday matters; memory problems; trouble following simple commands.
Behavior: personality or behavior changes.
Neurological: seizures, especially with no history of seizures.
Other: hearing problems; dizziness or vertigo (a sense that the world is spinning); feeling very hungry and gaining weight.
Why Do Brain Tumor Headaches Feel Different?
Headaches are the most common symptom of brain tumors, occurring in about half of people with brain tumors. A growing tumor can press on healthy cells around it, and it can also cause swelling in the brain that increases pressure in the head.
Brain tumor headaches are often worse when you wake up in the morning, though they can happen at any time. Some people have headaches that wake them from sleep. They tend to be worse when coughing or straining, and most often feel like a tension headache, though some people describe them as migraines.
The location of the tumor can shape the headache: tumors in the back of the head might cause a headache with neck pain, while tumors in the front of the head might feel like eye pain or sinus pain.
How Do Symptoms Change Based on Tumor Location?
The main part of the brain, the cerebrum, is divided into lobes, and each lobe controls different functions. A tumor in a given lobe tends to produce symptoms tied to that lobe's job.
Frontal lobe (front of the brain), thinking and voluntary movement: balance problems and trouble walking; personality changes such as forgetfulness and lack of interest in usual activities, sometimes noticed first by family members.
Parietal lobe (upper middle), temperature, taste, touch, movement, and sensory processing: problems related to the senses, including vision problems and hearing problems.
Occipital lobe (back of the brain), vision: vision loss.
Temporal lobe (sides of the brain), memories and integrating taste, sound, sight, and touch: memory problems; seeing, tasting, or smelling something that isn't there, sometimes unpleasant or unusual.
What Causes Brain Tumors?
What Causes a Primary Brain Tumor?
Brain tumors that start as a growth of cells in the brain are called primary brain tumors. They might start right in the brain or in tissue nearby, including the membranes that cover the brain (the meninges), the nerves, the pituitary gland, and the pineal gland.
Brain tumors happen when there are changes in the DNA of the cells in or near the brain. A cell's DNA holds the instructions that tell the cell what to do. The changes tell cells to grow quickly and to continue living when healthy cells would die as part of their natural life cycle. This makes a lot of extra cells that can form a tumor, and the tumor can grow to invade and destroy healthy tissue.
It's not clear what causes the DNA changes that lead to brain tumors. For many people with brain tumors, the cause is never known. Sometimes parents pass DNA changes to their children, increasing the risk of having a brain tumor, but these hereditary brain tumors are rare. If you have a family history of brain tumors, talk about it with your healthcare professional; you might consider meeting with a genetics-trained healthcare professional to understand whether your family history increases your risk.
What Is the Difference Between a Primary and a Metastatic Brain Tumor?
A primary brain tumor starts in the brain or its surrounding tissue. A secondary (metastatic) brain tumor begins as cancer in another part of the body, such as the breast, lung, colon, kidney, or skin (melanoma), and then spreads, or metastasizes, to the brain. Metastatic brain tumors are far more common than primary brain tumors.
What Are the Risk Factors for Brain Tumors?
Age: brain tumors are most common in older adults, but they are also among the most common cancers in children. Children are more likely to develop certain types of brain tumors, while adults tend to develop other types.
Radiation exposure: exposure to ionizing radiation, such as radiation therapy used to treat cancer, increases the risk of developing brain tumors.
Family history: a small portion of brain tumors occur in people with a family history of brain tumors. Some people inherit conditions that increase the risk of developing a brain tumor.
What Are the Different Types of Brain Tumors?
There are more than 100 types of primary brain tumors, and many are rare. Each type forms from a different kind of brain or nervous system cell and behaves differently.
Meningioma: the most common primary brain tumor in adults; usually benign; starts in the meninges, the membranes covering the brain.
Gliomas: a large group including astrocytomas, ependymomas, oligodendrogliomas, and glioblastomas.
Acoustic neuroma: a tumor of the vestibular (balance) nerve.
Medulloblastoma: the most common cancerous childhood brain tumor; starts in the lower back part of the brain; can spread within the cerebrospinal fluid pathways to other areas of the brain.
Other common types: craniopharyngiomas, schwannomas, pituitary tumors, pineal gland tumors, primitive neuroectodermal tumors (PNETs), and germ cell tumors.
What Does Tumor Grade Mean?
Brain tumors are graded from 1 to 4 based on how the cells look and how fast they grow. Grade 1 tumor cells look most like normal brain cells and grow slowly. Grade 4 tumor cells look very different from normal cells and grow fast, making them aggressive.
Benign tumors tend to grow slowly. Cancerous tumors grow quickly. Grade helps your healthcare team predict behavior and choose treatment.
What Are the Complications of a Brain Tumor?
Pressure is the central danger. A growing tumor sits inside the rigid skull, and it can press on the brain, causing swelling and increased pressure. This pressure can damage the brain and, in serious cases, be life-threatening. Symptoms of this pressure include headache, nausea, vision problems, confusion, and personality changes.
Pressure and swelling: the tumor grows in the rigid skull, increasing pressure; this can damage the brain and be life-threatening.
Seizures: the tumor irritates brain tissue. Learn more about tonic-clonic (grand mal) seizures.
Neurological loss: both the tumor itself and its treatments can lead to lasting vision, hearing, speech, memory, balance, and movement losses.
How Is a Brain Tumor Diagnosed?
What Tests Confirm a Brain Tumor?
Neurological examination: your healthcare professional examines your vision, hearing, balance, coordination, strength, and reflexes. Problems in one or more of these areas may provide clues about which part of the brain is being affected.
MRI: the most commonly used imaging test to help diagnose brain tumors. Specialized MRI variants (functional MRI, perfusion MRI, and MR spectroscopy) can provide extra information about the tumor.
CT scan: may also be used, sometimes with dye to highlight abnormalities.
PET scan: metabolic imaging of the tumor.
Biopsy: determines whether a tumor is benign or malignant and assigns its grade. Tumor cells can be taken during surgery or by a needle biopsy. The cells are analyzed in a lab to study how fast the tumor is growing and what the cells look like.
CT of the chest, abdomen, and pelvis: if a brain tumor might be secondary, this scan looks for cancer elsewhere in the body.
Lumbar puncture (spinal tap): collects cerebrospinal fluid to check for cancer cells.
What Is the Prognosis for a Brain Tumor?
Prognosis depends on many individual factors: whether the tumor is a brain cancer or benign, its type, size, grade, and location within the brain, which DNA changes are present in the tumor cells, whether it can be removed completely with surgery, and your overall health and well-being. The figures below are averages for groups of people and cannot predict any individual outcome.
Survival, all types combined: the average one-year survival rate is about 40%, the five-year rate is about 19%, and the ten-year rate is 13%.
After brain tumor metastasis: life expectancy is often between 3 and 12 months, or closer to 12 to 15 months with focused stereotactic radiosurgery (SRS) for limited metastasis. Living three years or longer is possible but uncommon (about 5%), usually when treatments work very well.
Glioblastoma (grade 4): average life expectancy of 6 to 9 months at age 65 or older, 20 months at ages 18 to 44, and 15 months at age 17 or younger.
Diffuse midline glioma (grade 4): average life expectancy of less than one year.
Anaplastic astrocytoma (grade 3): average life expectancy of 25 months.
Anaplastic oligodendroglioma (grade 3): average life expectancy of 15 years; about 20% survive five years or less.
Common causes of death from brain tumors include the tumor pressing on critical parts of the brain and preventing the brain from doing essential tasks, as well as pressure, swelling, bleeding, and infections that result from brain tumors. If you would like to know more about your prognosis, discuss it with your healthcare team.
How Is a Brain Tumor Treated?
Treatment depends on whether the tumor is cancerous or benign, its type, size, grade, location, the DNA changes present in the tumor cells, whether it can be removed completely with surgery, and your overall health and preferences.
Can a Brain Tumor Be Treated Without Immediate Surgery?
Yes, in some cases. If your brain tumor is small, benign, and causes no symptoms, treatment might not be needed right away. Small benign tumors might not grow at all, or might grow so slowly that they never cause problems. In these cases, your healthcare team may order brain MRI scans a few times a year to check for growth. If the tumor grows faster than expected or you develop symptoms, treatment then begins.
What Does Brain Tumor Surgery Involve?
The goal of surgery is to remove all of the tumor cells. That is not always possible. When complete removal isn't feasible, the surgeon removes as much of the tumor as can be done safely. Removing only part of a tumor is called a subtotal resection, and even partial removal may reduce your symptoms. Small tumors that are easy to separate from surrounding brain tissue are likely to be removed completely. Tumors that cannot be separated from surrounding tissue, or that sit near an important part of the brain, may be too risky to remove fully.
Craniotomy: the most common method. Part of the skull is removed: the scalp is cut, skin and muscles are moved aside, and a drill removes a section of skull bone. The tumor is cut out with special tools, sometimes using lasers. You are numbed and placed in a sleeplike state, and the skull bone is put back at the end.
Awake brain surgery: during a craniotomy, you may be awakened so the surgeon can ask questions and monitor brain activity as you respond, lowering the risk of hurting important brain areas.
Endoscopic brain surgery: a long, thin tube (endoscope) with a camera is inserted, and special tools pass through it to remove the tumor.
Endoscopic transnasal transsphenoidal surgery: a surgical instrument is placed through the nostril, alongside the nasal septum, to reach a pituitary tumor.
Surgery carries risks. Possible complications include infection, bleeding, blood clots, and injury to brain tissue, as well as vision loss if the tumor is near the nerves that connect to the eyes, and hearing loss if the tumor is near the nerve that controls hearing.
What Does Radiation Therapy Do?
Radiation therapy uses powerful energy beams, from X-rays, protons, or other sources, to kill tumor cells. It usually comes from a machine outside the body (external beam radiation); rarely, radiation is placed inside the body (brachytherapy). Radiation treats both brain cancers and benign tumors.
Treatment is usually delivered in short daily sessions, commonly five days a week for 2 to 6 weeks. Radiation can be focused on the area around the tumor, or, when there are many tumors, applied to the entire brain (whole-brain radiation), most often used for cancer that has spread to the brain from elsewhere.
Proton therapy is a newer form that may be less likely to hurt nearby healthy tissue because the beams are more carefully targeted. It may help children and tumors very close to important brain structures, but it is not as widely available as traditional X-ray radiation.
Common side effects during or right after treatment include fatigue, headaches, memory loss, scalp irritation, and hair loss. Some side effects appear years later, including memory and thinking problems.
What Is Radiosurgery, and How Is It Different from Surgery?
Stereotactic radiosurgery is not surgery at all; it involves no cut in the skin. It aims many small beams of radiation from different angles at the tumor. Each beam is weak, but where the beams meet, the combined dose is large enough to kill tumor cells. Radiosurgery treats both brain cancers and benign tumors. It is typically completed in one or a few treatments, and you go home the same day. Side effects include fatigue and scalp skin changes: the skin may feel dry, itchy, and sensitive, with possible blisters or hair loss, which is sometimes permanent.
Linear accelerator (LINAC) machines: aim carefully shaped X-ray beams one at a time from several angles (known by brand names such as CyberKnife and TrueBeam).
Gamma Knife: aims many small gamma-ray beams at the tumor at the same time.
Proton radiosurgery: uses proton beams; the newest type, becoming more common but not available at all hospitals.
How Do Chemotherapy and Targeted Therapy Work for Brain Tumors?
Chemotherapy uses strong medicines to kill tumor cells. It can be taken as a pill, injected into a vein, or placed directly into brain tissue during surgery. It treats both brain cancers and benign tumors and is sometimes given at the same time as radiation therapy. Side effects depend on the drugs and dose and can include nausea, vomiting, and hair loss.
Targeted therapy uses medicines that attack specific chemicals present within the tumor cells. By blocking these chemicals, targeted treatments cause tumor cells to die. Targeted therapy is available for certain types of brain cancers and benign tumors, and your tumor cells may be tested to see whether a targeted drug is likely to help you.
What Recovery Help Exists After Brain Tumor Treatment?
After treatment, you might need help regaining function in the part of your brain that had the tumor: help with moving, speaking, seeing, and thinking. Based on your needs, your healthcare professional might suggest:
Physical therapy: regaining lost motor skills or muscle strength.
Occupational therapy: getting back to typical daily activities, including work.
Speech therapy: help if speaking is difficult.
Tutoring (school-age children): coping with changes in memory and thinking.
Can Complementary Treatments Help?
Little research has been done on complementary and alternative brain tumor treatments, and no alternative treatment has been proven to cure brain tumors. However, complementary approaches may help you cope with the stress of a diagnosis. Options include art therapy, exercise, meditation, music therapy, and relaxation exercises. Talk with your healthcare team about your options.
How Should You Prepare for a Brain Tumor Appointment?
If you have worrying symptoms, start with your usual healthcare professional. If a brain tumor is diagnosed, you may be referred to specialists: neurologists (brain conditions), medical oncologists (medicine-based cancer treatment), radiation oncologists (radiation-based cancer treatment), neuro-oncologists (nervous system cancers), neurosurgeons (brain and nervous system surgery), rehabilitation specialists, and psychologists or behavioral psychologists who specialize in memory and thinking problems.
To prepare: be aware of any pre-appointment restrictions (such as diet); write down every symptom, including ones that seem unrelated; note key personal information like major stresses or recent life changes; list all medicines, vitamins, and supplements; consider bringing a family member or friend who can help remember what is said; and write down your questions, ranking your top three as most important.
Questions worth asking: What type of brain tumor do I have? Where is it located and how large is it? How aggressive is it? Is it cancerous? Will I need additional tests? What are my treatment options, and can any cure the tumor? What are the benefits and risks of each? Which treatment is best for me? What happens if the first treatment doesn't work or if I decline treatment? What is the survival rate for my diagnosis? Should I see a specialist, and will insurance cover it? Should I seek care at a center experienced in brain tumors? What determines follow-up visits?
Expect your healthcare professional to ask: when symptoms began; whether they are constant or come and go; how severe they are; and what improves or worsens them.
Conclusion: Why Brain Tumor Awareness and Prompt Evaluation Matter
A brain tumor is an abnormal, uncontrolled growth of cells in the brain, benign or malignant, whose symptoms depend on size, location, and growth rate. Headache, especially one that is worse in the morning or changes in pattern, is the single most common warning sign. Because symptoms can be subtle for months or strike suddenly within days, persistent neurological changes deserve evaluation rather than explanation away. Diagnosis relies on imaging and biopsy, and treatment ranges from careful watchful waiting with regular MRIs to surgery, radiation, radiosurgery, chemotherapy, and targeted therapy. The most important step anyone can take is getting persistent symptoms checked early.
If you or a loved one is experiencing persistent headaches, new vision or speech problems, weakness, balance trouble, or a first seizure, make an appointment with a healthcare professional without delay.
Frequently Asked Questions (FAQ)
What is the most common symptom of a brain tumor?
Headache is the most common symptom, occurring in about half of people with brain tumors. Brain tumor headaches are often worse in the morning, may wake you from sleep, and tend to worsen with coughing or straining. They most often feel like a tension headache.
What does a brain tumor headache feel like?
Most people describe it as a tension headache, and some describe it as a migraine. It may come with pressure in the head, nausea or vomiting, and it often worsens when waking, coughing, or straining. Tumors in the back of the head can cause headaches with neck pain; tumors in the front can feel like eye or sinus pain.
Are all brain tumors cancer?
No. Brain tumors can be benign (noncancerous) or malignant (cancerous). Benign tumors tend to cause symptoms that develop slowly over months or years, while cancerous tumors cause symptoms that appear suddenly and worsen within days or weeks. Even benign tumors can damage the brain by pressing on nerves and blood vessels.
How fast do brain tumor symptoms develop?
It depends on whether the tumor is cancerous. Benign tumors usually cause symptoms that develop slowly, with subtle signs that worsen over months or years. Malignant tumors cause symptoms that come on suddenly and worsen in a matter of days or weeks.
Can a brain tumor cause personality changes?
Yes. Tumors in the frontal lobes, which control thinking and movement, can cause personality changes such as forgetfulness and lack of interest in usual activities. Family members sometimes notice that the person with the tumor seems different before the person does.
Can a brain tumor make you smell or taste things that aren't there?
Yes. Tumors in the temporal lobes, which process memories and senses, can cause a person to see, taste, or smell something that isn't there. The taste or smell is sometimes unpleasant or unusual.
What lobe of the brain controls vision, and what happens when a tumor grows there?
The occipital lobe, at the back of the brain, primarily controls vision. Tumors in the occipital lobe can cause vision loss.
What symptoms does a temporal lobe tumor cause?
Temporal lobe tumors, on the sides of the brain, can cause memory problems and can make someone see, taste, or smell something that isn't there, sometimes unpleasant or unusual tastes or smells.
What causes brain tumors?
Brain tumors begin when changes occur in the DNA of cells in or near the brain. The changes tell cells to grow quickly and to survive when healthy cells would die, creating extra cells that form a tumor. For many people, the cause of these DNA changes is never known.
Are brain tumors inherited?
Sometimes parents pass DNA changes to their children, and these changes can increase brain tumor risk, but hereditary brain tumors are rare. If you have a family history, discuss it with your healthcare professional; a genetics-trained professional can help you understand whether your family history raises your risk.
What are the risk factors for brain tumors?
The main risk factors are age (brain tumors are most common in older adults but are also among the most common cancers in children), exposure to ionizing radiation such as prior radiation therapy, and a family history of brain tumors or inherited conditions that raise risk.
What is the difference between a primary and a secondary brain tumor?
A primary brain tumor starts in the brain or nearby tissue such as the meninges, nerves, pituitary gland, or pineal gland. A secondary (metastatic) tumor begins as cancer elsewhere, such as the breast, lung, colon, kidney, or skin, and spreads to the brain. Secondary brain tumors are far more common than primary ones.
What is the most common brain tumor in adults?
Meningioma is the most common primary brain tumor in adults. It is usually benign and starts in the meninges, the membranes that cover the brain.
What is the most common brain cancer in children?
Medulloblastoma is the most common cancerous childhood brain tumor. It starts in the lower back part of the brain and can spread within the cerebrospinal fluid pathways to other areas of the brain.
What does brain tumor grade mean?
Grade describes how abnormal the tumor cells look and how fast they grow. Grade 1 cells look most like normal cells and grow slowly. Grade 4 cells look very different from normal cells and grow fast, making them aggressive.
How is a brain tumor diagnosed?
Diagnosis usually begins with a neurological exam of vision, hearing, balance, coordination, strength, and reflexes. MRI is the most commonly used imaging test; CT scans, PET scans, and specialized MRI variants may follow. A biopsy, done during surgery or with a needle, determines whether the tumor is benign or malignant and assigns its grade.
What happens if a brain tumor is small and not causing symptoms?
If the tumor is small, benign, and symptom-free, treatment may not be needed right away. Small benign tumors might never grow or might grow so slowly that they never cause problems. Your healthcare team may order brain MRI scans a few times a year to watch for growth and start treatment if the tumor grows faster than expected or symptoms appear.
What are the main treatments for brain tumors?
Treatment depends on whether the tumor is cancerous, its type, size, grade, location, DNA changes, removability, and your overall health. Options include surgery (craniotomy, endoscopic surgery), radiation therapy (including proton therapy), stereotactic radiosurgery, chemotherapy, targeted therapy, and, for small benign tumors, monitoring with regular MRI scans.
What is a craniotomy?
A craniotomy is brain surgery in which part of the skull is removed to reach the tumor. The surgeon cuts the scalp, moves skin and muscles aside, drills out a section of skull bone, removes the tumor (sometimes using lasers), and replaces the skull bone afterward. You are numbed and placed in a sleeplike state; sometimes you are awakened during surgery to protect important brain areas.
What is awake brain surgery?
During some craniotomies, patients are awakened so the surgeon can ask questions and monitor brain activity as they respond. This helps lower the risk of damaging important parts of the brain.
What is stereotactic radiosurgery, and is it actual surgery?
No, it involves no cut in the skin. Many small beams of radiation are aimed at the tumor from different angles; each beam is weak, but where they meet, the combined dose is large enough to kill tumor cells. It is typically done in one or a few treatments, and you go home the same day.
What are the side effects of radiation therapy for brain tumors?
Common side effects during or right after treatment include fatigue, headaches, memory loss, scalp irritation, and hair loss. Some side effects appear years later, including memory and thinking problems.
Can brain tumors be treated with targeted therapy?
Yes, for certain types. Targeted therapy medicines attack specific chemicals present within tumor cells, and blocking these chemicals can cause tumor cells to die. Your tumor cells may be tested to see whether targeted therapy is likely to help.
What is whole-brain radiation, and when is it used?
Whole-brain radiation applies radiation to the entire brain rather than just the tumor area. It is most often used when cancer has spread to the brain from another part of the body and has formed multiple tumors.
What rehabilitation helps after brain tumor treatment?
You may need help regaining function in the part of the brain that had the tumor. Physical therapy helps with motor skills and muscle strength, occupational therapy with daily activities and work, and speech therapy if speaking is difficult. Tutoring can help school-age children cope with memory and thinking changes.
What is the survival rate for brain tumors?
The average one-year survival rate for all brain cancers and tumors combined is about 40%, the five-year rate is about 19%, and the ten-year rate is 13%. Individual prognosis depends on tumor type, grade, location, DNA changes, removability, and overall health, so discuss your own prognosis with your healthcare team.
Is brain tumor prognosis the same for everyone?
No. Prognosis varies widely based on whether the tumor is cancerous, its type, size, grade, location, DNA changes, whether surgery can remove it completely, and your overall health. The averages quoted in this article describe groups, not individuals.
Sources and Further Reading
References
Medical disclaimer: This article is for general informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read here. If you think you may have a medical emergency, call your local emergency number immediately.
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