Does type 1 diabetes cause frequent urination?

This symptom reflects fluid being pulled into urine rather than a simple bladder problem. It may appear with thirst, tiredness, increased hunger or unintentional weight loss. Urinary infection, increased fluid intake, caffeine and some medicines can also cause frequency. The symptom itself cannot establish diabetes, so a glucose check and clinical review are appropriate.

Seek prompt medical assessment for new frequent urination, especially when it is paired with thirst, fatigue or weight change. A clinician may test blood glucose and urine and assess hydration. Drink water to replace losses, but avoid using sweet drinks as treatment. Keep a note of when you urinate, night-time episodes, thirst and any medicines, as this can help the assessment.

Go to emergency care if frequent urination occurs with vomiting, abdominal pain, deep or rapid breathing, fruity breath, confusion or unusual sleepiness. These symptoms can accompany diabetic ketoacidosis, a serious state caused by too little insulin. A person with known type 1 diabetes who cannot keep fluids down or has ketones should use their sick-day instructions and seek urgent advice.

Ask whether blood glucose, urine glucose or ketone testing is suitable, and how quickly results should be reviewed. Discuss other possible causes, warning signs, fluid advice and what to do if symptoms worsen overnight.