What Are the Causes of Spontaneous Paralysis of Part of the Body?

Paralysis, or the inability to move or feel part of the body, is a symptom of many disorders and afflictions. While paralysis can occur due to stroke or back injury, other causes of paralysis are less well known. Experiences of spontaneous paralysis are not necessarily signs of a life-threatening illness, but they should always be checked out by a doctor.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.


Stroke is a form of cerebrovascular disease, when the brain is robbed of oxygen. The most common symptoms of stroke are weakness, paralysis in part of the body or only one side of the body, and tiredness. Because even small strokes can result in brain damage if not treated quickly, immediate medical care is essential.

Heart Attack

Paralysis, pain or tingling of the left arm, or more uncommonly the right arm, can be a sign of heart attack. Often the arm feels weak, and this may be accompanied by other symptoms such as profuse sweating. Contrary to popular belief, chest pain is felt in only about half of sufferers of heart attacks. A person who thinks he may be having heart attack should seek emergency medical care immediately.

Food Poisoning

Sudden paralysis can be related to food poisoning. A classic case is published in the State of Alaska Epidemiology Bulletin in which a man who ate butter clams, a kind of shellfish, began having breathing difficulties and then a deepening paralysis of the body.


Rabies is a constant public health threat. Caused by a bite by an animal infected with the rabies virus, early symptoms include tingling and itching at the site of the bite. Later symptoms include paralysis and possibly death. Because rabies often cannot be cured, pets should always be vaccinated against the illness.


Spontaneous paralysis can also be due to the sleep disorder narcolepsy. Known as cataplexy, the symptom involves sudden loss of muscle tone in certain parts of the body, such as the hands or face, or the entire body. Strong emotions can bring on this symptom of narcolepsy, which also involves periods of sudden sleepiness during the day and insomnia at night, according to the National Heart Lung and Blood Institute.

Sleep Paralysis

Waking up feeling paralyzed is also associated with narcolepsy. Known as sleep paralysis, this harmless feeling is due to a glitch in the body’s sleep/wake cycle. Many people also experience sleep paralysis without symptoms of narcolepsy when under stress and fatigued.