Excessive thirst is an abnormally strong desire to drink liquids. It can related to an underlying medical condition.
Increased thirst is not considered excessive when it is related to a recent lack of drinking fluids. Also, people who have always had a strong desire to drink a lot of fluids are not considered to have excessive thirst. There are many potential causes for this condition.
When a person complains of an excessive amount of thirst, the healthcare professional needs to know: when the problem startedwhether the person feels dehydrated or has a dry mouthwhether the thirst is constant or occurs only at certain timeswhat types of liquids the person drinks each dayhow much the person drinks each daywhether the person has increased or decreased the amount of fluids he or she drinks each daywhether the person's weight has changedhow much the person exerciseswhat other medical conditions the person may havewhat medications, drugs, or herbs a person may be takingwhether the person is having any other symptoms
Other questions may also be asked, depending on the history and physical findings, if any.
There are many possible causes for excessive thirst. These include: increased exercise, which can increase the body's water requirementsdehydration. This occur from any of a number of causes including diarrhea, infection, hot weather, vomiting, or the use of medications called diuretics that eliminate fluid from the body.hormone imbalances. These may include a high level of thyroid hormone, a condition called hyperthyroidism, or a high level of adrenal hormones, called hyperadrenalism.hypernatremia, which is a high level of sodium in the bodyuncontrolled diabetes. This is a condition that causes an increase in blood sugar levels, triggering excessive thirst.diabetes insipidus. Diabetes insipidus is a disease that causes people to urinate excessively and results in dehydration.certain drugs or medications. The use of antihistamines, marijuana, caffeine, or alcohol can cause this condition.psychogenic polydipsia, which is a psychiatric condition that causes a person to feel thirsty for no apparent reasondamage to an area of the brain called the hypothalamus. This is rare.
Other causes are also possible. Sometimes, no cause can be found.
Prevention is often not possible. Drinking extra fluids before exercising can help prevent excessive thirst in this setting. Avoiding drugs and other substances responsible for excessive thirst can prevent these cases due. Taking medications as prescribed and checking blood sugars regularly can prevent some cases due to diabetes.
Sometimes the cause is obvious from the medical history and physical exam. In other cases, further testing is needed, depending on what is suspected. For example, a blood glucose level can be used to detect diabetes. A serum sodium test, usually performed as part of a broader blood chemistry panel, can detect hypernatremia. A blood alcohol level test can detect alcohol use. An x-ray test called a cranial CT scan may be done if brain damage is suspected.
Long-term effects are related to the cause. Uncontrolled diabetes can cause damage to many organs and even result in death. Cases due to dehydration can usually be treated successfully without long term effects. A person with psychogenic polydipsia can sometimes develop dangerous salt imbalances due to excessive water drinking.
Excessive thirst is not contagious and poses no risks to others. If the cause of excessive thirst is dehydration due to an infection, the infection may be contagious.
Treatment is directed at the cause. For example, a person with diabetes may use insulin injections or other medications to control blood sugar levels. Someone who is dehydrated is given fluids.
If a person is unable to drink extra fluid, it can be supplied an through an intravenous (IV) tube, usually inserted in the arm. This may be necessary if a person is vomiting and cannot hold fluids down.
Someone with hyperthyroidism may need medication, surgery, or radioactive therapy to treat the condition. A person who abuses drugs may need drug rehabilitation. An individual who has psychogenic polydipsia is often treated with psychotherapy, and possibly medications.
Side effects depend on the treatments used. For example, medications can cause allergic reactions, stomach upset or headaches. Surgery can be complicated by bleeding, infection, or a reaction to the anesthetic.
Once treated, a person with dehydration often needs no further treatment. Someone with diabetes needs lifelong monitoring and treatment for their diabetes. An individual who stops abusing drugs may not longer experience excessive thirst.
Any changes or response to treatment can be reported to the healthcare professional. Other monitoring is related to the cause. For example, an individual with diabetes needs to check his or her blood sugar levels every day.
Harrison's Principles of Internal Medicine, 1998, Fauci et al.
