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)
- Head injury
- Liver cirrhosis
- 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)
- Diabetes mellitus
- 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?
What are the potential complications of thirst?
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
- Kidney damage
- Unconsciousness and coma
- Worsening of an underlying condition
- Thirst - excessive. MedlinePlus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ency/article/003085.htm.
- Thirst - absent. MedlinePlus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ency/article/003086.htm.
- Domino FJ (Ed.) Five Minute Clinical Consult. Philadelphia: Lippincott Williams & Wilkins, 2013.
- Collins RD. Differential Diagnosis in Primary Care, 5th ed. Philadelphia: Lippincott, Williams & Williams, 2012.
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... Read more about thirstintroduction
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 thirstAn absence of thirst may accompany other symptoms including:
- Absent or excessive sweating
- Change in mental status such as confusion or hal... Read more about thirstsymptoms