6 Most Common UTI Symptoms

Dr. Clarisse Bezerra
Revisão médica: Dr. Clarisse Bezerra
Family Doctor
March 2021

UTI symptoms can vary a lot from one person to another, and according to the affected region in the urinary system, which can be the urethra, the bladder or the kidneys.

However, the classic symptoms of a urinary tract infection (UTI) include:

  1. Pain or burning sensation when peeing;
  2. Feeling of weight in the bladder;
  3. Urinary urgency;
  4. Peeing in small quantities;
  5. Very dark and strong-smelling urine;
  6. Persistent low grade fever (under 38ºC or 100.4ºF).

Generally, urinary tract infections are caused by the bacteria in the intestines that reach the urinary system, and that's why UTI's are more frequent in women, since the anus is closer to the urethra than in men.

Online symptom checker 

If you think that you may have a UTI, please select your symptoms:

  1. 1.Pain or burning sensation when peeing
  2. 2.Frequent and sudden urge to urinate in small quantities
  3. 3.Feeling of not being able to empty the bladder
  4. 4.Heavy sensation or discomfort in the bladder area
  5. 5.Cloudy urine or with the presence of blood
  6. 6.Persistent low fever (under 38º C or 100.4º F)

Different types of UTI

A UTI can affect different locations in the urinary system. Thus, depending on the affected location, the UTI can be divided into different types:

1. Urethritis: infection in the urethra 

Urethritis happens when the bacteria causing the UTI only infects the urethra, causing inflammation and symptoms like :

  • Frequent urination;
  • Difficulty peeing;
  • Pain or burning sensation when peeing;
  • Yellow discharge in the urethra.

In these cases it is recommended to visit a doctor in order to start treatment with antibiotics to get rid of the bacteria in the urethra. You should also keep the area clean and dry, as well as increase your daily water intake.

2. Cystitis: bladder infection 

Bladder infection is a common form of UTI and it happens when the bacteria manages to pass the urethra and get to the bladder, causing:

  • Urgent need to urinate, but in small quantities;
  • Burning sensation when peeing;
  • Presence of blood in the urine;
  • Cloudy urine with an intense and unpleasant smell;
  • Abdominal pain or feeling of weight at the bottom of your stomach;
  • Fever up to 38ºC (100.4ºF).

We recommend you visit a urologist or a G.P. as soon as one or more of these symptoms appear so you can start treatment with antibiotics and stop the infection from getting to your kidneys.

If you have back pain, fever over 38 ºC (100.4ºF) or vomiting you will need to go to the E.R. immediately.

3. Pyelonephritis: kidney infection

Most UTIs affect only the urethra or the bladder, however, in more serious cases the bacteria can reach the kidneys and cause a serious infection that leads to:

  • Fever over 38.5º C (101.3º F);
  • Strong abdominal pain in the stomach, back or groin;
  • Pain or burning sensation when urinating;
  • Cloudy urine;
  • Presence of pus or blood in the urine;
  • Frequent need to pee.

In addition, you may also have chills, nausea, vomiting or fatigue. In elderly people, this type of infection usually causes confusion even before other symptoms appear.

If you suspect you might have pyelonephritis, go to the hospital immediately to identify the problem and start treatment with intravenous antibiotics.

UTI symptoms in babies 

Identifying UTI symptoms in babies can be hard, as babies and children can't usually explain what they are feeling. In these cases, however, the most common symptoms are:

  • Fever over 37.5ºC (99.5º F) with no apparent cause;
  • Crying when peeing;
  • Urine with an intense smell;
  • Presence of blood in the diaper;
  • Constant irritability;
  • Loss of appetite.

If these symptoms appear, please visit a pediatrician to assess whether the child has developed a UTI.

UTI symptoms during pregnancy 

UTI symptoms in pregnancy are the same as when you are not pregnant, and many times you may not have any symptoms at all, and the infection is only discovered after doing a routine urine test.

During pregnancy UTIs are more common, due to a lower immune system and an increase in urine proteins which cause increase and development of bacteria.

Pregnancy UTIs can be treated with antibiotics considered safe during pregnancy and include Cephalexin and Nitrofurantoin. 

How to confirm the diagnosis

The diagnosis is confirmed through urinalysis. You can also do other tests, such as a urine culture test and an antibiogram, to find out which bacteria is involved and to see which is the best antibiotic to use. 

Medical diagnostic tests, such as ultrasound and magnetic resonance imaging, can also be requested, especially in case of pyelonephritis.

What causes UTIs 

A UTI is caused by bacteria entering the urinary system, the most common being: Escherichia coli (about 70% of cases), Staphylococcus saprophyticus, Proteus and Klebsiella species and Enterococcus faecalis. 

How to avoid a UTI 

To avoid a UTI we recommend that you:

  • Wash the external genital area with soap and water after sexual intercourse;
  • After urinating and passing stool always clean the genitals starting at the front and going to the back, to avoid E. Coli bacteria getting to the vagina;
  • Empty your bladder every time you pee to avoid residual urine, which increases the probability of getting a UTI;
  • Drink more water, taking in at least 1.5 liters clear liquids a day;
  • Have a diet rich in fibers to decrease the time the feces remain in the intestines, which decreases the time the bacteria stays inside the body;
  • Do not apply perfume or cream with any type of chemical to the vaginal area, since it can irritate the skin and increase the risk of UTIs;
  • Avoid wearing clothes that are too tight and avoid wearing a daily pantyliner, so you don't sweat excessively in that area. 

Follow these recommendations daily, especially during pregnancy, when there is a higher risk of getting a UTI due to hormonal changes and the increase of weight on the bladder which encourages bacteria to proliferate. 

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Atualizado por Equipe Tua Saúde - em March de 2021. Revisão médica por Dr. Clarisse Bezerra, Family Doctor - em March de 2021.


  • RORIZ-FILHO, Jarbas S. et al. Infecção do trato urinário. Revista da Faculdade de Medicina de Ribeirão Preto. 118-125, 2010
  • FIORAVANTE, Flávia. Tecnologia educacional para a prevenção da infecção urinária na gravidez: estudo descritivo. Tese de Mestrado, 2015. Universidade Federal Fluminense.
Revisão médica:
Dr. Clarisse Bezerra
Family Doctor
Dr. Bezerra possesses a medical degree and specializes in family medicine. She is licensed to practice under CRM-CE licence #16976.