Nervous System Problems

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

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

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

• Reference Numbness, tingling Opens New Window, weakness, or inability to move a part or all of one side of the body (Reference paralysis Opens New Window).
• 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.
• Reference Confusion Opens New Window or a change in Reference level of consciousness Opens New Window or Reference behavior.
• Severe nausea or vomiting.

Reference Seizures Opens New Window 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 Reference Seizures.

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

Reference Vertigo Opens New Window and Reference dizziness Opens New Window are problems of balance and coordination (equilibrium). Vertigo is often caused by a Reference medicine or a problem of the inner ear or brain. Emotional distress, Reference dehydration Opens New Window, blood pressure problems, and other diseases can all cause feelings of dizziness. For more information, see the topic Reference 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 Reference migraine Opens New Window, to severe pain that comes and goes over several days, such as with Reference cluster headaches Opens New Window. Headaches are usually caused by problems with the sinuses, scalp, or muscles of or around the head. For more information, see the topic Reference Headaches.

Reference Check your symptoms to decide if and when you should see a doctor.

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This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Reference Terms of Use. Reference How this information was developed to help you make better health decisions.