Hydrochlorothiazide (HCTZ) is approved by the US Food and Drug Administration to treat high blood pressure and edema. Edema is swelling from retained fluid. Edema often occurs with conditions such as heart failure.

Some doctors also prescribe HCTZ for:

  • Kidney stones
  • Diabetes insipidus (a hormone problem that leads to too much urination)
  • Hypoparathyroidism (underactive parathyroid glands that can cause low blood calcium)
  • Meniere’s disease (dizziness and ringing in the ears)
  • Bone loss and osteoporosis