Hi, thank you for using Healthcare Magic.
I had gone through your question and understand your question.
Frequent urination or polyuria is found among people take Cephalexin, especially for people who are female and have
high blood pressure.
Here are the other condition with polyuria:
1. Type 2 diabetes, In addition to the symptoms of polyuria, patients will usually eat more, very thirsty, more frequent sleep, and experience drastic
weight loss.
2. Pregnancy (woman), because the enlarged womb press the bladder.
3. Use of diuretic like furosemide, that used to treat
hypertension or manage excessive fluid in body.
By now, if it's not bothering you, I suggest you to continue use cephalexin until it runs out according to the time set by the doctor because this drug is an antibiotic. Do not stop usage before the specified time even if the condition is cured.
Then, if it's still happen and bothersome, contact your treating doctor, so he/she can do some test that might be needed like blood glucose,
urinalysis, and ultrasound (USG) to rule out any other condition.
Hope this answer your question.
Wishing you a good health.