Feeling thirsty all the time and for no obvious reason is not normal and should be investigated by your GP.
Normally, a feeling of thirst is the brain's way of warning you that you're dehydrated, because you're not drinking the amount of fluid that your body needs. You can soon quench your thirst and restore the fluid balance in your body after having a drink.
But when thirst is excessive and persistent, it could be a sign of diabetes or another underlying condition. Doctors call abnormal thirst 'polydipsia'.
This page gives specific advice as to when you should see your GP and explains when thirst may be a sign of diabetes.
Points to consider
It's worth thinking about what you've been eating and drinking recently. Eating lots more spicy or salty foods can cause a sudden increase in thirst.
Thirst can also result from losing excessive amounts of water from the body. This can happen after:
- intense exercising (because of the water lost through sweating)
- diarrhoea and/or vomiting
Also, is the problem actually a dry mouth, rather than thirst? See the box on this page for information on dry mouth.
When you should see your GP
You should see your GP if:
- you feel thirsty all the time for no apparent reason or
- you're experiencing other symptoms too, such as fatigue or passing a lot of urine
Your GP will probably carry out a blood glucose test to see if you have diabetes.
Diabetes clues
As well as feeling thirsty, people with diabetes will usually find they are going to the toilet a lot (especially at night) and will feel very tired.
Having diabetes means that your body is unable to break down glucose into energy. This is because there is either not enough insulin to move the glucose or because the insulin that is there does not work properly.
For more information on this condition, read our pages on the symptoms, diagnosis and treatment of diabetes.
