NHS Factsheet

NHS website

Excessive thirst

Find out about excessive thirst, including what might be causing it, when to see a GP and the difference between dry mouth and excessive thirst.

9 May 2023

Introduction

It's normal to sometimes feel thirsty, but it's not normal to constantly feel thirsty even when you're drinking a lot. See a GP to find out what's causing your excessive thirst.

Why am I always thirsty?

Most of the time if you're feeling thirsty it's because you need to drink more fluids.

This can happen if you:

  • sweat a lot after doing exercise
  • are unwell with sickness and diarrhoea
  • do not drink enough fluids
  • drink too much alcohol or caffeine
  • eat salty or spicy food
  • have a high temperature
  • are pregnant

Important

Drink more fluids and avoid alcohol or caffeine to see if it helps. If you do not, you may be at risk of becoming dehydrated.

See a GP if you have excessive thirst and:

  • drinking more fluids for several days has not helped
  • you frequently need to pee
  • you're pregnant

The GP will check if your excessive thirst is being caused by something – for example, diabetes ↗, anaemia ↗ or medicines you're taking.

The treatment you have will depend on what's causing your excessive thirst.

Dry mouth or excessive thirst?

You may think you're thirsty when you actually have a dry mouth.

If it's a dry mouth, you may have:

  • a burning sensation or soreness in your mouth
  • changes in your sense of taste
  • difficulty speaking, eating or swallowing

Find out more about dry mouth ↗