Symptoms of too little fluid and too much fluid

The main symptom of too little fluid is thirst. Others include:

  • not passing very much urine, urine is dark and strong-smelling

  • dry or sticky mouth, coated ('furry') tongue, cracked lips

  • feeling dizzy, especially when you stand up.

The symptoms of too much fluid include:

  • passing a lot of urine

  • swollen ankles

  • feeling breathless, especially when you lie flat.