Chills, or shivering, often are just a symptom of exposure to cold temperatures or a rapid shift in temperatures to which the body is exposed. Severe chills that last more than an hour and are not easily alleviated can be a symptom of rare diseases or conditions such as hantavirus or malaria. The common causes of severe chills, though, usually are easily treated at home and don't require treatment from a physician.
Most often, severe chills indicate the onset of the flu or another virus. Other infections or inflammations in the body, such as a urinary tract infection or pneumonia, can also cause a case of severe chills. Chills that cause violent and uncontrollable shaking all over the body often indicate a systemic infection — one that has spread throughout the body — and may warrant a visit to the doctor or hospital emergency room.
A person with severe chills may feel very cold, even when wearing heavy clothes or wrapped in quilts or heavy blankets in a warm room. These symptoms usually signal the presence of inflammation or fever, which makes the body temperature higher than normal. Severe chills can also be a symptom of hypothermia, in which the body's temperature is lower than normal, even dangerously so.
Side effects or allergic reactions to prescription medications can cause chills, along with common medical procedures such as a blood transfusion. Heat stroke can also cause a case of severe chills. Other medical conditions can result in symptoms of chills, including pleurisy, psoriasis, pneumonia or a chest infection. Meningitis, a heart valve infection, and even the common cold can cause severe chills.
Serious infections sometimes result after surgery or other medical conditions such as childbirth or miscarriage. Puerperal fever sometimes develops, and this condition can advance into puerperal sepsis, a serious form of septicemia. Severe chills following childbirth or miscarriage should be taken seriously and treated by a physician; puerperal sepsis can be life-threatening. Common infections, such as an abscessed tooth or an infected wound, can also trigger severe chills. People with heart valve abnormalities and those who have recently undergone dental work may be subject to chills.
One of the most common causes of severe chills is hypothermia. The body usually maintains a healthy temperature on its own, which rises and falls during the day and night in reaction to normal temperature cycles and external conditions. Certain medical conditions, such as cardiovascular disease and malnutrition, may predispose a person to hypothermia. If the body is exposed to severe cold, especially with high humidity and severe wind chill, hypothermia can rapidly set in. The body's natural control mechanisms become unable to regulate a normal temperature, losing more warmth that the body is able to generate.
Symptoms of hypothermia are indications that medical treatment is necessary. These symptoms include shivering and severe chills, slurred speech and pale skin, and very slow breathing. A person with hypothermia often loses coordination and feels lethargic. The hypothermic patient may also be confused, and often loses mental function very gradually. Babies with hypothermia and chills often have cold skin that appears bright red.
If a person has severe chills and shows other signs of hypothermia, you should call 9-1-1, watch the person's breathing very carefully and, if it stops, begin cardiopulmonary resuscitation (CPR) immediately. Keep the person warm and out of the wind, and use warm, dry blankets or clothing to cover the skin. Do not use hot water or any kind of heating device to try to warm the person. Don't try to warm the legs and arms — this can exacerbate hypothermia by causing the core body temperature to fall. Warm beverages are good, but do not give the person any kind of alcohol.
