Why does my urine smell like onions?

UTI : Either you are eating too many onions or you have uti.

Can be diet, etc..: This might be due to diet like from eating vegetables like asparagus, or it can be from a medical condition like diabetes which can cause a fruity odor in the breath and urine from ketone production. It may also be nonspecific.

Urinary Odors: Urine odors typically come from what we've eaten or meds we've taken more than from worrisome illnesses. If there aren't any symptoms of infection such as urgency/frequency, burning with urination or bladder pain, i'd likely suspect it's something that will get better on its own. If it persists or any of the above symptoms arise, especially if feverish, go see your primary doctor.