context: A urinary tract infection ( UTI) starts when bacteria get into your bladder, kidneys, or another part of your urinary tract. The best way to treat a UTI -- and to relieve symptoms like pain, burning, and an urgent need to pee -- is with antibiotics. These medications kill bacteria that cause the infection. It's important to take them just as your doctor prescribed. A minor UTI can turn into a serious kidney or blood infection if you don't. Which antibiotic you get and how long you take it depend on two things: what kind of bacteria caused your infection and how severe your UTI is. Your doctor will take a urine sample to confirm that you have a UTI. Then the lab will grow the germs in a dish for a couple of days to find out which type of bacteria you have. This is called a culture. It'll tell your doctor what type of germs caused your infection. He'll likely prescribe one of the following antibiotics to treat it before the culture comes back: Amoxicillin/augmentin Ceftriaxone ( Rocephin) Cephalexin ( Keflex) Ciprofloxacin ( Cipro) Fosfomycin ( Monurol) Levofloxacin ( Levaquin) Nitrofurantoin ( Macrodantin, Macrobid) Trimethoprim/sulfamethoxazole ( Bactrim, Septra) Which medication and dose you get depends on whether your infection is complicated or uncomplicated. â Uncomplicatedâ means your urinary tract is normal. â Complicatedâ means you have a disease or problem with your urinary tract. You could have a narrowing of your ureters, which are the tubes that carry urine from your kidneys to your bladder, a narrowing in the urethra which transports urine from the bladder out of the body, or, you might have a blockage like a kidney stone or an enlarged prostate (in men). To treat a complicated infection, your doctor might prescribe a higher dose of antibiotics. If your UTI is severe or the infection is in your kidneys, you might need to be treated in a hospital or doctor's office with high-dose antibiotics you get through an IV. Your doctor will also consider these factors when choosing an antibiotic: Are you pregnant? Are you over age 65? Are you allergic to any antibiotics? Have you had any side effects from antibiotics in the past? Your doctor will let you know. Typically, for an uncomplicated infection, you'll take antibiotics for 2 to 3 days. Some people will need to take these medicines for up to 7 to 10 days. For a complicated infection, you might need to take antibiotics for 14 days or more. A follow-up urine test can show whether the germs are gone. If you still have an infection, you'll need to take antibiotics for a longer period of time. If you get UTIs often, you may need to take low-dose antibiotics every day for 6 months or longer. And if sex causes your UTIs, you'll take a dose of the medicine right before you have sex. You can also take antibiotics whenever you get a new UTI. There are some, as is the case with any medicines you take. Some of these include: Rash Diarrhea Nausea, vomiting Headache Tendon or nerve damage Antibiotics work well against UTIs. You might start to feel better after being on the medicine for just a few days. But even so, keep taking your medicine. If you stop your antibiotics too soon, you won't kill all the bacteria in your urinary tract. These germs can become resistant to antibiotics. That means the meds will no longer kill these bugs in the future. So if you get another UTI, the medication you take might not treat it. Take the full course of your medicine to make sure all the bacteria are dead. Your UTI symptoms should improve in a few days. Call your doctor if: Your symptoms don't go away Your symptoms get worse Your symptoms come back after you've been treated You have bothersome side effects from your antibiotics