Thirst
Thirst
If you feel thirsty all the time, without any clear reason, it isn't something to brush aside. It's worth getting checked by your doctor.
Normally, thirst is simply your brain's way of telling you that your body is low on fluid and needs more to drink. But when thirst becomes excessive and just won't go away (doctors call this polydipsia), it can be a sign that something else is going on, such as diabetes.
Common Symptoms
Symptom information is not available for this condition yet.
⚠️ This symptom list is for educational purposes. Having these symptoms does not mean you have this condition. See a doctor for proper diagnosis.
Medicines Commonly Used
⚠️ These medicines are commonly used for confirmed diagnoses of this condition. This is NOT a recommendation or prescription. Treatment must be determined by your doctor.
No medicines have been linked to this condition yet.
Causes
Feeling thirsty usually just means your body isn't getting the fluid it needs. This can happen after heavy sweating, or after losing fluid through diarrhoea and vomiting.
You can usually quench your thirst and restore your body's fluid balance simply by having a drink and making sure you stay well hydrated. Staying well hydrated matters especially during hot weather, during exercise, and while you're unwell with vomiting and diarrhoea.
Food
Sometimes thirst has a simple explanation, like a recent meal or snack. Eating salty or spicy food can leave you suddenly feeling thirsty.
Diabetes
If you feel thirsty all the time, it could point to diabetes, especially if you also notice other symptoms such as needing to urinate frequently, feeling extremely tired, or losing weight without trying. Diabetes is a lifelong condition that makes it hard for your body to control the amount of sugar (glucose) in your blood. When glucose levels are high, your kidneys have to produce more urine to help flush the extra glucose out of your body. This fluid loss is what makes you feel thirsty, as your brain urges you to drink more to replace what's been lost.
If you're constantly thirsty and have other symptoms like these, your GP will probably arrange a blood glucose test to check for diabetes.
Pregnancy
Feeling thirsty and needing to urinate more often than usual is common during pregnancy and is usually nothing to worry about. Very occasionally, though, these signs can point to gestational diabetes, a form of diabetes that develops during pregnancy. If you're at risk, screening for this should be part of your routine antenatal care.
Medication
Sometimes, excessive thirst is a side effect of certain medicines, including lithium, some antipsychotics, and diuretics (water tablets). If you suspect a medicine is behind your thirst, it may be possible to switch to a different one or adjust the dose. Talk to your GP before making any changes.
Other causes of thirst
Severe thirst can also have a number of other underlying causes, including:
- diabetes insipidus, a condition caused by problems with a hormone that regulates the body's fluid levels
- diabetic ketoacidosis, a dangerous complication of diabetes caused by a lack of the hormone insulin
- sickle cell anaemia, an inherited blood disorder
- psychogenic polydipsia, where a person with a mental health condition, such as schizophrenia, drinks unusually large amounts of water that the kidneys cannot get rid of
- excessive bleeding