Myasthenia gravis, sometimes called MG, is a chronic (long-lasting) disease that causes weakness in your voluntary muscles. The voluntary muscles are the ones that you can control. They include the muscles you use for:

• Eye and eyelid movement
• Facial expressions
• Chewing
• Talking
• Swallowing
• Breathing
• Moving your arms and legs

You can also have weakness in other muscles. This weakness gets worse with activity, and better with rest.

Myasthenia gravis is a type of autoimmune disease. In autoimmune diseases, your immune system attacks the healthy cells of your organs and tissues by mistake.

Myasthenia gravis is caused by an error in how nerve signals are sent to muscles. These signals get blocked at the nerve-muscle junction. This junction is the place where the nerve endings connect with the muscles they control.

Normally, this is how the signals work:

• The signals travel down a nerve that controls movement in the muscle
• The nerve endings release a substance called acetylcholine
• Acetylcholine binds to the muscle tissue at the nerve-muscle junction
• This causes the muscle to contract (move)

But in someone with myasthenia gravis, the body's own immune system makes antibodies that block the binding of acetylcholine to the muscle. This makes the muscles weaker.

The thymus gland, which is part of your immune system, may play a role in myasthenia gravis. Normally, your thymus gland is active and growing when you are a child. It makes white blood cells to fight infections. At puberty, it starts getting smaller and is replaced by fat. It is usually small by the time you are an adult. But in many adults with myasthenia gravis, the thymus gland stays large. And some people with myasthenia gravis can get thymomas, which are tumors of the thymus. The are usually benign (not cancer), but they can sometimes become cancerous.

Although myasthenia gravis can affect people of any age, it is most common in young adult women (under age 40) and older men (over age 60). It is usually not inherited (passed down in families).

Myasthenia gravis normally does not affect infants. But if you are pregnant and have myasthenia gravis it's possible to pass the antibodies to your fetus. The baby can then be born with neonatal myasthenia. This condition is usually temporary, and the symptoms typically go away within two to three months after birth.

The symptoms of myasthenia gravis will depend on which muscles are affected. The symptoms often include:

• Weakness of the eye muscles
• Drooping of one or both eyelids
• Blurred or double vision
• Changes in facial expressions
• Trouble swallowing
• Shortness of breath
• Speech problems
• Weakness in the arms, hands, fingers, legs, and neck

Different people have different levels of muscle weakness. And the weakness can vary from day to day. Some days it might be mild, and other days it might be worse. Physical activity often makes the muscle weakness worse.

Some people with myasthenia gravis can get severe weakness that affects the muscles that control breathing. This is called a myasthenic crisis, and it is a life-threatening emergency.

There are many other conditions that can cause muscle weakness, so myasthenia gravis can be hard to diagnose. To find out if you have myasthenia gravis, your health care provider:

• Will ask about your medical history and symptoms
• Will do a physical exam, including a neurological exam
• Will likely order tests for myasthenia gravis, including:
  • Blood tests
  • Imaging tests
  • Electromyography (EMG) and nerve conduction studies

There is no cure for myasthenia gravis, but treatments that can improve muscle weakness and help with symptoms. They include:

• Anticholinesterase medicines, which can improve nerve-to-muscle messages and make muscles stronger.
• Immunosuppressive medicines, which are medicines that decrease your body's immune system responses. They can lower your body's production of abnormal antibodies.
• Monoclonal antibodies, which can also help decrease your body's immune system responses.
• Plasmapheresis (plasma exchange) and intravenous immunoglobulin, which are procedures to remove abnormal antibodies from your blood. They are usually used in severe cases. They can help with symptoms for a few weeks or months.
• Thymectomy, surgery to remove the thymus gland. It can reduce the symptoms of myasthenia gravis, possibly by rebalancing the immune system.

Lifestyle changes may be helpful for some people. The changes could include regular gentle exercise, getting enough rest, and eating healthy foods.

Some people with myasthenia gravis go into remission. This means that they do not have symptoms. The remission is usually temporary, but sometimes it can be permanent.

NIH: National Institute of Neurological Disorders and Stroke

Nausea is when you feel sick to your stomach, as if you are going to throw up. Vomiting is when you throw up.

Nausea and vomiting can be symptoms of many different conditions, including:

• Morning sickness during pregnancy
• Gastroenteritis (infection of your intestines) and other infections
• Migraines
• Motion sickness
• Food poisoning
• Medicines, including those for cancer chemotherapy
• GERD (reflux) and ulcers
• Intestinal obstruction

Nausea and vomiting are common. They are usually not serious. However, you should contact your health care provider immediately if you have:

• A reason to think that your vomiting is from poisoning
• Vomited for longer than 24 hours
• Blood in the vomit
• Severe abdominal pain
• Severe headache and stiff neck
• Signs of dehydration, such as dry mouth, infrequent urination or dark urine

Your health care provider will take your medical history, ask about your symptoms and do a physical exam. The provider will look for signs of dehydration. You may have some tests, including blood and urine tests. Women may also have a pregnancy test.

Treatments for nausea and vomiting depend on the cause. You may get treatment for the underlying problem. There are some medicines that can treatment nausea and vomiting. For severe cases of vomiting, you may need extra fluids through an IV (intravenous).

There are things that you can do to feel better:

• Get enough fluids, to avoid dehydration. If you are having trouble keeping liquids down, drink small amounts of clear liquids often.
• Eat bland foods; stay away from spicy, fatty, or salty foods
• Eat smaller meals more often
• Avoid strong smells, since they can sometimes trigger nausea and vomiting
• If you are pregnant and have morning sickness, eat crackers before you get out of bed in the morning

Neurofibromatosis is a genetic disorder of the nervous system. It mainly affects how nerve cells form and grow. It causes tumors to grow on nerves. You can get neurofibromatosis from your parents, or it can happen because of a mutation (change) in your genes. Once you have it, you can pass it along to your children. Usually the tumors are benign, but sometimes they can become cancerous.

There are three types of neurofibromatosis:

• Type 1 (NF1) causes skin changes and deformed bones. It usually starts in childhood. Sometimes the symptoms are present at birth.
• Type 2 (NF2) causes hearing loss, ringing in the ears, and poor balance. Symptoms often start in the teen years.
• Schwannomatosis causes intense pain. It is the rarest type.

Doctors diagnose the different types based on the symptoms. Genetic testing is also used to diagnose NF1 and NF2. There is no cure. Treatment can help control symptoms. Depending on the type of disease and how serious it is, treatment may include surgery to remove tumors, radiation therapy, and medicines.

NIH: National Institute of Neurological Disorders and Stroke

The brain, spinal cord, and nerves make up the nervous system. Together they control all the workings of the body. When something goes wrong with a part of your nervous system, you can have trouble moving, speaking, swallowing, breathing, or learning. You can also have problems with your memory, senses, or mood.

There are more than 600 neurologic diseases. Major types include:

• Diseases caused by faulty genes, such as Huntington's disease and muscular dystrophy
• Problems with the way the nervous system develops, such as spina bifida
• Degenerative diseases, where nerve cells are damaged or die, such as Parkinson's disease and Alzheimer's disease
• Diseases of the blood vessels that supply the brain, such as stroke
• Injuries to the spinal cord and brain
• Seizure disorders, such as epilepsy
• Cancer, such as brain tumors
• infections, such as meningitis

Nutrition is about eating a healthy and balanced diet so your body gets the nutrients that it needs. Nutrients are substances in foods that our bodies need so they can function and grow. They include carbohydrates, fats, proteins, vitamins, minerals, and water.

Good nutrition is important, no matter what your age. It gives you energy and can help you control your weight. It may also help prevent some diseases, such as osteoporosis, high blood pressure, heart disease, type 2 diabetes, and certain cancers.

But as you age, your body and life change, and so does what you need to stay healthy. For example, you may need fewer calories, but you still need to get enough nutrients. Some older adults need more protein.

Some changes that can happen as you age can make it harder for you to eat healthy. These include changes in your:

• Home life, such as suddenly living alone or having trouble getting around
• Health, which can make it harder for you to cook or feed yourself
• Medicines, which can change how food tastes, make your mouth dry, or take away your appetite
• Income, which means that you may not have as much money for food
• Sense of smell and taste
• Problems chewing or swallowing your food

To stay healthy as you age, you should:

• Eat foods that give you lots of nutrients without a lot of extra calories, such as
  • Fruits and vegetables (choose different types with bright colors)
  • Whole grains, like oatmeal, whole-wheat bread, and brown rice
  • Fat-free or low-fat milk and cheese, or soy or rice milk that has added vitamin D and calcium
  • Seafood, lean meats, poultry, and eggs
  • Beans, nuts, and seeds
• Avoid empty calories. These are foods with lots of calories but few nutrients, such as chips, candy, baked goods, soda, and alcohol.
• Pick foods that are low in cholesterol and fat. You especially want to try to avoid saturated and trans fats. Saturated fats are usually fats that come from animals. Trans fats are processed fats in stick margarine and vegetable shortening. You may find them in some store-bought baked goods and fried foods at some fast-food restaurants.
• Drink enough liquids, so you don't get dehydrated. Some people lose their sense of thirst as they age. And certain medicines might make it even more important to have plenty of fluids.
• Be physically active. If you have started losing your appetite, exercising may help you to feel hungrier.

Sometimes health issues or other problems can make it hard to eat healthy. Here are some tips that might help:

• If you are tired of eating alone, try organizing some potluck meals or cooking with a friend. You can also look into having some meals at a nearby senior center, community center, or religious facility.
• If you are having trouble chewing, see your dentist to check for problems
• If you are having trouble swallowing, try drinking plenty of liquids with your meal. If that does not help, check with your health care provider. A health condition or medicine could be causing the problem.
• If you're having trouble smelling and tasting your food, try adding color and texture to make your food more interesting
• If you aren't eating enough, add some healthy snacks throughout the day to help you get more nutrients and calories
• If an illness is making it harder for you to cook or feed yourself, check with your health care provider. He or she may recommend an occupational therapist, who can help you find ways to make it easier.

NIH: National Institute on Aging