Overview

The nervous system is a complex, highly specialized network. It organizes, explains, and directs interactions between you and the world around you. The nervous system controls:

• Sight, hearing, taste, smell, and feeling (sensation).
• Voluntary and involuntary functions, such as movement, balance, and coordination. The nervous system also regulates the actions of most other body systems, such as blood flow and blood pressure.
• The ability to think and reason. The nervous system allows you to be conscious and have thoughts, memories, and language.

The nervous system is divided into the brain and spinal cord ( central nervous system , or CNS) and the nerve cells that control voluntary and involuntary movements ( peripheral nervous system , or PNS).

The symptoms of a nervous system problem depend on which area of the nervous system is involved and what is causing the problem. Nervous system problems may occur slowly and cause a gradual loss of function (degenerative). Or they may occur suddenly and cause life-threatening problems (acute). Symptoms may be mild or severe. Some serious conditions, diseases, and injuries that can cause nervous system problems include:

• Blood supply problems (vascular disorders).
• Injuries (trauma), especially injuries to the head and spinal cord.
• Problems that are present at birth (congenital).
• Mental health problems, such as anxiety disorders , depression , or psychosis .
• Exposure to toxins, such as carbon monoxide, arsenic, or lead.
• Problems that cause a gradual loss of function (degenerative). Examples include:
  • Parkinson's disease .
  • Multiple sclerosis (MS) .
  • Amyotrophic lateral sclerosis (ALS) .
  • Alzheimer's disease .
  • Huntington's disease .
  • Peripheral neuropathies .
• Infections. These may occur in the:
  • Brain ( encephalitis or abscesses ).
  • Membrane surrounding the brain and spinal cord ( meningitis ).
• Overuse of or withdrawal from prescription and nonprescription medicines, illegal drugs , or alcohol.
• A brain tumor .
• Organ system failure. Examples include:
  • Respiratory failure.
  • Heart failure.
  • Liver failure (hepatic encephalopathy).
  • Kidney failure (uremia).
• Other conditions. Some examples include:
  • Thyroid dysfunction ( overactive or underactive thyroid ).
  • High blood sugar ( diabetes ) or low blood sugar ( hypoglycemia ).
  • Electrolyte problems .
  • Nutritional deficiencies, such as vitamin B1 (thiamine) or vitamin B12 deficiency.
  • Guillain-Barré syndrome .

A sudden (acute) nervous system problem can cause many different symptoms, depending on the area of the nervous system involved. Stroke and transient ischemic attack (TIA) are common examples of acute problems. You may experience the sudden onset of one or more symptoms, such as:

• Numbness, tingling , weakness, or inability to move a part or all of one side of the body ( paralysis ).
• Dimness, blurring, double vision, or loss of vision in one or both eyes.
• Loss of speech, trouble talking, or trouble understanding speech.
• Sudden, severe headache.
• Dizziness, unsteadiness, or the inability to stand or walk, especially if other symptoms are present.
• Confusion or a change in level of consciousness or behavior.
• Severe nausea or vomiting.

Seizures can also cause sudden changes in consciousness, feeling (sensation), emotion, or thought. Abnormal body movements, such as muscle twitching, may or may not be present. How often the seizures occur and how severe they are depend on the cause of the seizures and the area of the brain involved. For more information, see the topic Seizures .

Diabetes can cause problems with balance, either as a result of peripheral neuropathy or stroke.

Vertigo and dizziness are problems of balance and coordination (equilibrium). Vertigo is often caused by a medicine or a problem of the inner ear or brain. Emotional distress, dehydration , blood pressure problems, and other diseases can all cause feelings of dizziness. For more information, see the topic Dizziness: Lightheadedness and Vertigo .

Most headaches are not caused by serious central nervous system problems. The pain that comes with a headache can range from a throbbing or a piercing pain, such as with a migraine , to severe pain that comes and goes over several days, such as with cluster headaches . Headaches are usually caused by problems with the sinuses, scalp, or muscles of or around the head. For more information, see the topic Headaches .

Home Treatment

Specific home treatment for symptoms related to a nervous system problem depends on the cause of the problem. Check your symptoms to determine if and when you need to see your doctor. Keep a diary of your symptoms to review with your doctor at your next appointment. See an example of a diary of symptoms .

Symptoms to watch for during home treatment

Call your doctor if your symptoms become more frequent or severe during home treatment.

Prevention

Follow the prevention guidelines below to keep your body and nervous system healthy:

• Exercise regularly. Talk to your doctor about an exercise plan that will be right for you.
• Do not smoke or use other tobacco products. For more information, see the topic Quitting Smoking .
• Get plenty of rest.
• Take care of health conditions that may cause decreased nervous system functioning, such as:
  • Diabetes .
  • High blood pressure .
• Eat a balanced diet. A balanced, low-fat diet with ample sources of vitamins B6, B12, and folate will help protect the nervous system. Make sure that your diet contains lots of fresh fruits, vegetables, and whole grains.
• Drink plenty of water and other fluids. This helps prevent dehydration , which can cause confusion and memory problems.
  • To prevent dehydration during hot weather and exercise, drink water, rehydration drinks, or other fluids each day.
  • Drink extra water before, during, and after exercise . Take a container of water or sports drink with you when you exercise, and try to drink at least every 15 to 20 minutes.
  • Limit your intake of caffeinated drinks, such as coffee and colas, which increase dehydration and can affect sleep.
• Do not use alcohol or illegal drugs, which can affect functioning long after use.
• Have your hearing or vision tested. When you do not hear or see well, it is hard for your brain to record information.
• Set priorities, and concentrate on one thing at a time. Older adults have a harder time than younger people giving their attention to more than one activity.
• Increase your attention span and ability to focus by learning new skills.
• Keep written notes. Write all your plans on a calendar where you can look at them often.
• Use a medicine box with spaces for each day. This will help you remember when to take your medicines. Take your medicines exactly as they are prescribed.
• Decrease your use of nonprescription medicines. Overuse of medicines may be the single biggest cause of nervous system problems in older adults.
• Develop a positive attitude about your abilities. Reject the notion that nervous system (neurological) functioning declines with age.
• Protect yourself from head injuries .
• Prevent falls in your home.

Preparing For Your Appointment

To prepare for your appointment, see the topic Making the Most of Your Appointment .

You can help your doctor diagnose and treat your condition by being prepared to answer the following questions:

• What is your main symptom?
• When did you first notice your nervous system problem, and what were you doing at the time?
• How often have you had these symptoms?
• What area of your body is most affected?
• How long do the symptoms last?
• Do you have pain? If so, what is it like (dull, sharp, aching, throbbing)? It may be helpful to keep a pain diary .
• What seems to make your symptoms better or worse?
• Do you have other symptoms? Other symptoms may include:
  • Vision loss.
  • Weakness.
  • Lack of coordination.
• Do you use alcohol or illegal drugs?
• What prescription and nonprescription medicines do you take, and what are the doses? Bring all of your medicines with you to your next appointment.
• Have you had a recent illness or injury?
• Does anyone in your family have similar symptoms?
• Have you recently traveled outside of the country?
• Do you have any health risks ?

Keep a diary of symptoms to review with your doctor at your next appointment.