What is thirst?
Thirst is the desire to drink fluids, and it is a normal, everyday feeling. Depending on your activities and diet, you may notice changes in how thirsty you feel during a particular day and on different days. Major changes in your patterns of thirst, however, may be symptoms of a disease or medical condition.
A lack of thirst, especially if it lasts longer than a day, or an abrupt change in your normal pattern of thirst can be a symptom of a number of conditions. A lack of thirst can indicate head injuries, liver disease, specific types of cancer, or stroke.
Excessive thirst, especially when prolonged, or a sudden change in your thirst pattern can also be a symptom of a number of conditions. Excessive thirst can signal possible bleeding, diabetes, physical exhaustion, dehydration, or a mental disorder. Some medications can lead to excessive thirst.
The outcome and complications associated with abnormal thirst depend entirely on the underlying cause. It is usually appropriate to drink fluids when you are thirsty and not to drink fluids when you are not thirsty. If you suspect that your thirst patterns are not normal, or if you notice a sudden change in your thirst, it is important to contact a physician to determine the cause of these symptoms.
Seek prompt medical care if you notice excessive thirst, an absence of thirst, or a sudden change in your thirst patterns lasting more than a couple of days.
If abnormalities in your thirst are persistent or cause you concern, seek prompt medical care.
What other symptoms might occur with thirst?
An absence or excess of thirst may accompany other symptoms, which vary depending on the underlying disease, disorder or condition.
Common symptoms that may occur along with an absence of thirst
An absence of thirst may accompany other symptoms including:
Absent or excessive sweating
Change in mental status such as confusion or hallucinations
Malaise or lethargy
Muscle spasms or cramps
Nausea with or without vomiting
Seizures and tremors
Unconsciousness and coma
Common symptoms that may occur along with excessive thirst
Excessive thirst may accompany other symptoms including:
Blurred or double vision
Change in mental status, such as confusion
Fever and chills
Malaise or lethargy
Passing large quantities of urine
Serious symptoms that might indicate a life-threatening condition
In some cases, an absence or excess of thirst may be a symptom of a life-threatening condition that should be immediately evaluated in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms including:
What causes thirst?
Your body maintains a certain level of fluids, and your level of thirst is your body’s way of telling you it needs more or less fluid. Thirst can increase normally if you lose a lot of fluid, such as during a workout, and can decrease normally if you have enough fluid, such as after drinking a lot of water.
An absence of thirst or excessive thirst can be caused by a number of conditions and diseases. The thirst can be a symptom associated with too much or too little water in your body, or it can be a change in your perception of thirst, even though fluid levels in your body are normal.
Common causes of an absence of thirst
An absence of thirst may be caused by a variety of situations and conditions including:
Being adequately hydrated (normal)
Recently drinking fluid (normal)
Syndrome of inappropriate antidiuretic hormone secretion (SIADH), which can be caused by a specific type of lung cancer
Tumor or injury involving the hypothalamus, the region of your brain that regulates thirst
Common causes of excess thirst
Excess thirst can be caused by a variety of situations and conditions including:
Dehydration (loss of body fluids and electrolytes, which can be life threatening when severe and untreated)
Diabetes insipidus (lack of antidiuretic hormone)
Ingestion of unusually salty or spicy foods
Medication side effects
Organ failure (failure of the heart, kidney or liver)
Psychogenic polydipsia (excessive consumption of water without cause or stimulus)
Rapid fluid loss, such as during a workout, when in a hot environment, or as a result of profuse vomiting or diarrhea
Questions for diagnosing the cause of excessive thirst or absence of thirst
To diagnose your condition, your doctor or licensed health care practitioner will ask you several questions related to your thirst including:
When did you first notice changes in your thirst?
Do you have any other symptoms associated with your thirst?
Are your symptoms worse during the day or at night?
Does your thirst change throughout the day?
Have you changed your diet or exercise patterns?
Have you gained or lost weight recently?
What medications are you taking?
Complications associated with too much or too little thirst vary widely, depending on the underlying cause. In almost all cases, it is important to drink more if you are thirsty and to consume adequate fluid each day, even if you are not thirsty. Because the level of fluids in your body is essential for your well-being, it is very important that any underlying disease that affects your thirst is diagnosed. You can help minimize your risk of serious complications by following the treatment plan you and your health care professional design specifically for you. Complications of too much or too little thirst include:
Adverse effects of treatment
Unconsciousness and coma
Worsening of an underlying condition