What are the side effects of hydrochlorothiazide?

While taking hydrochlorothiazide capsules you may experience dizziness, hair loss or stomach upset. You may feel lightheaded when sitting or standing too rapidly or you may have episodes of blurry vision. Do not drive or engage in hazardous activities until you know how hydrochlorothiazide will affect you. If these side effects persist or worsen, contact your doctor. Also, let your doctor know right away if you experience any of the following side effects, as they may be signs of a medical emergency:

  • an allergic reaction, such as hives or an itchy rash, swelling around the mouth or face, or chest tightness and difficulty breathing
  • signs of an infection, such as fever, chills or a sore throat that doesn't go away
  • severe stomach upset or dizziness
  • swelling or redness, especially if its located in the joint of the big toe
  • confusion or mood swings
  • difficulty urinating or dark urine
  • fainting or seizures
  • irregular heartbeat
  • muscle cramps or soreness
  • numbness
  • red, blistering or peeling skin
  • shortness of breath
  • unexplained bruising or bleeding
  • feeling drowsier than normal
  • feeling restless, tired or weak
  • dry mouth
  • vomiting
  • joint pain
  • yellowing of the eyes or skin

Based on information from, a free medication monitoring service, 25% of patients experience side effects while taking Hydrochlorothiazide (Microzide, Oretic). Some of the side effects reported by iGuard members include: Urinary Frequency, Dizziness, Heat Sensitivity, and Electrolyte Problems. Please follow up with your doctor or other healthcare provider if you are experiencing any symptoms that worsen or do not go away.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.