The distinct smell of urine is impossible to miss, whether it's wafting from a kid's diaper, lingering on a subway platform, or coming out of your own body. Technically, pee is mostly made up of water and some waste product from your kidneys, which is the special ingredient that gives it its signature scent, according to the Mayo Clinic.
Sometimes, you might notice that your pee smells aggressively strong or just a little bit off-kilter. For example, it might be musty, sour, sweet, rotten, or something in between. Depending on the cause, your pee might return to its normal odor after a day. If a change in scent is accompanied by something more obviously disconcerting (like blood in your urine or pain with urination), or it simply doesn't return to normal, that's reason enough to contact your doctor. Ahead, find five common causes for a change in your urine — and take note of which ones could signal a more serious problem.