neuritides

Nerves are like wires that carry messages back and forth between your brain and your body. Your peripheral nerves branch off from your brain and spinal cord and connect to all parts of your body, including your muscles and organs. Peripheral nerves carry messages from your brain that control your movement, breathing, heartbeat, digestion, and more. They also carry messages from your body to your brain, so you can feel things, such as pain, heat, and cold.

Peripheral nerve disorders happen when one or more peripheral nerves are damaged. Damaged nerves may not carry messages correctly, or they may not work at all. As a result, you may have pain, trouble walking, or a variety of other problems, depending on which nerves are involved.

Peripheral nerve disorders are very common. There are more than 100 different types.

Many things can damage nerves and lead to peripheral nerve disorders:

• Diabetes is the most common cause of peripheral nerve disorders. Most people with diabetes will develop diabetic nerve problems.
• Physical injury (trauma) that stretches, crushes, squeezes, cuts, or puts pressure on one or more nerves. Some examples of peripheral nerve disorders from physical injury include complex regional pain syndrome and brachial plexus injuries.
• Health conditions, including:
  • Certain cancers and their treatment (chemotherapy and radiation therapy).
  • Infections, such as HIV and Lyme disease.
  • Problems with blood or blood vessels.
  • Autoimmune diseases, such as rheumatoid arthritis and lupus.
  • Kidney or liver disease.
• Certain medicines.
• Contact with certain toxic substances, such as lead or mercury.
• Alcohol use disorder (AUD) and smoking.
• Vitamin imbalances, especially a lack of vitamin B12.
• Your genes, including changes in your genes or conditions that you inherit from your parents, such as Charcot-Marie-Tooth disease.

In certain cases, the cause of peripheral nerve disorder is not known.

The symptoms of peripheral nerve disorders depend on which nerves are affected, what is causing the damage, and how serious it is:

• Weak or aching muscles
• Problems with balance, walking, or using your arms and hands
• Cramps or twitching muscles
• Muscle shrinking

• Tingling, numbness, or pain often in the hands and feet
• Not being able to feel heat, cold, or pain, such as a cut on your foot
• Pain from even light touch

• A heartbeat that's too fast or too slow
• Trouble swallowing
• Sweating too much or too little
• Vomiting, diarrhea, or constipation
• Problems with urination or sexual function

Symptoms may range from mild to very strong. They may develop quickly over days or slowly over months and years. But they are rarely life-threatening.

To find out if you have a peripheral nerve disorder, your provider will:

• Ask about your medical history
• Ask about your family health history
• Do a physical exam
• Order tests, which may include:
  • Blood tests
  • Genetic tests
  • Nerve tests that measure:
    • Electrical activity in your nerves and muscles
    • How well your autonomic nerves are working
  • A biopsy of nerve or skin tissue
  • CT or MRI scan to see what may be pressing on your nerves

It's important to treat any conditions that are causing nerve damage. In certain cases, that will allow your nerves to heal over time.

Treatment for symptoms depends on the type of peripheral nerve disorder you have, where it is, and how severe. Treatment options include:

• Braces or splints
• Over-the-counter patches and skin creams
• Prescription medicines
• Non-drug pain management, such as electrical stimulation or relaxation therapy
• Surgery to relieve pressure on a nerve

You can help prevent peripheral nerve disorders by:

• Managing health conditions that may cause nerve damage, especially diabetes
• Preventing falls and accidents
• Avoiding toxic substances
• Being careful to avoid repeated motions and body positions that press on your nerves
• Eating a balanced diet, exercising, limiting alcohol, and not smoking

NIH: National Institute of Neurological Disorders and Stroke

The optic nerve is a bundle of more than 1 million nerve fibers that carry visual messages. You have one connecting the back of each eye (your retina) to your brain. Damage to an optic nerve can cause vision loss. The type of vision loss and how severe it is depends on where the damage occurs. It may affect one or both eyes.

There are many different types of optic nerve disorders, including:

• Glaucoma is a group of diseases that are the leading cause of blindness in the United States. Glaucoma usually happens when the fluid pressure inside the eyes slowly rises and damages the optic nerve.
• Optic neuritis is an inflammation of the optic nerve. Causes include infections and immune-related illnesses such as multiple sclerosis. Sometimes the cause is unknown.
• Optic nerve atrophy is damage to the optic nerve. Causes include poor blood flow to the eye, disease, trauma, or exposure to toxic substances.
• Optic nerve head drusen are pockets of protein and calcium salts that build up in the optic nerve over time

Contact your health care provider if you are having vision problems. Tests for optic nerve disorders may include eye exams, ophthalmoscopy (an examination of the back of your eye), and imaging tests. Treatment depends on which disorder that you have. With some optic nerve disorders, you may get your vision back. With others, there is no treatment, or treatment may only prevent further vision loss.

When you're dizzy, you may feel lightheaded, woozy, or disoriented. If you feel like you or the room are spinning, you have vertigo. These feelings may make you lose your balance.

Dizziness can have many different causes. A sudden drop in blood pressure or being dehydrated can make you dizzy. Many people feel lightheaded if they get up too quickly from sitting or lying down. Certain medicines and problems with your inner ear may cause dizziness. So can motion sickness. Sometimes dizziness can be a symptom of other disorders.

As people get older, they may have more health problems and take more medicines. This makes them more likely to have problems with dizziness and balance.

Dizziness usually gets better by itself or is easily treated. If you are dizzy often, you should see your health care provider to find the cause.

NIH: National Institutes of Health

Ear infections are the most common reason parents bring their child to a doctor. Three out of four children will have at least one ear infection by their third birthday. Adults can also get ear infections, but they are less common.

The infection usually affects the middle ear and is called otitis media. The tubes inside the ears become clogged with fluid and mucus. This can affect hearing, because sound cannot get through all that fluid.

If your child isn't old enough to say "My ear hurts," here are a few things to look for:

• Tugging at ears
• Crying more than usual
• Fluid draining from the ear
• Trouble sleeping
• Balance difficulties
• Hearing problems

Your health care provider will diagnose an ear infection by looking inside the ear with an instrument called an otoscope.

Often, ear infections go away on their own. Your health care provider may recommend pain relievers. Severe infections and infections in young babies may require antibiotics.

Children who get infections often may need surgery to place small tubes inside their ears. The tubes relieve pressure in the ears so that the child can hear again.

NIH: National Institute on Deafness and Other Communication Disorders

Multiple sclerosis (MS) is a nervous system disease that affects your brain and spinal cord. It damages the myelin sheath, the material that surrounds and protects your nerve cells. This damage slows down or blocks messages between your brain and your body, leading to the symptoms of MS. They can include:

• Visual disturbances
• Muscle weakness
• Trouble with coordination and balance
• Sensations such as numbness, prickling, or "pins and needles"
• Thinking and memory problems

No one knows what causes MS. It may be an autoimmune disease, which happens when your immune system attacks healthy cells in your body by mistake. Multiple sclerosis affects women more than men. It often begins between the ages of 20 and 40. Usually, the disease is mild, but some people lose the ability to write, speak, or walk.

There is no specific test for MS. Doctors use a medical history, physical exam, neurological exam, MRI, and other tests to diagnose it. There is no cure for MS, but medicines may slow it down and help control symptoms. Physical and occupational therapy may also help.

NIH: National Institute of Neurological Disorders and Stroke