Why Do Urinary Tract Infections Increase in Winter? Facts and Prevention

When the weather turns cold, you often hear people say “I caught a chill and now I have a bladder infection.” Burning when passing urine, going to the toilet frequently and pain in the lower abdomen are complaints many people have in winter. But is it really the cold that causes the infection, or the habits that change in winter? In this article we compare common beliefs with the facts and list ways to protect yourself.

How does a urinary tract infection develop?

A urinary tract infection develops when bacteria enter through the urethra and multiply in the bladder (cystitis) or, travelling further, in the kidney (pyelonephritis). Bacteria from the bowel are responsible for the great majority of infections. In women, infection is more common because the urethra is short and close to the back passage. In men it is rarer and is often linked to an underlying cause such as an enlarged prostate or a stone.

In other words, the direct cause of the infection is not the cold but bacteria. The role of the cold is indirect.

Does sitting in the cold really cause a urinary tract infection?

Myth: Sitting on cold ground or on a stone, or getting chilled, causes a urinary tract infection.

Fact: Cold on its own does not cause an infection. However, exposure to cold narrows the body’s blood vessels and can make the kidneys produce more urine and the bladder signal the need to pass urine more often. This “going to the toilet all the time” is easily mistaken for an infection. A real infection, on the other hand, usually comes with additional symptoms such as burning, cloudy or foul-smelling urine and pain in the lower abdomen.

Why do urinary tract infections seem to increase in winter?

Research gives differing results on how infections are distributed across the seasons; some studies report that they are more common in the summer months. Nevertheless, some winter habits can increase the risk at an individual level:

• Drinking less water: The feeling of thirst decreases in the cold. When you drink less water, the bladder empties less often and it becomes easier for bacteria to multiply in it.
• Holding urine for long periods: Avoiding going to the toilet outdoors in the cold, long journeys and thick layers of clothing lead to putting off passing urine. Urine that sits for a long time is a favourable environment for bacteria.
• Constipation: With low fluid intake and inactivity, constipation can increase in winter. Constipation both makes it harder for the bladder to empty completely and can make it easier for bacteria to pass into the urinary tract.
• Cold remedies: Decongestants and some allergy medicines can make it harder to empty the bladder, especially in men with an enlarged prostate. Urine left in the bladder increases the risk of infection.
• Inactivity and time indoors: Less physical activity and long periods of sitting in winter can also have a negative effect on general habits.

Does cranberry juice cure a urinary tract infection?

Myth: Cranberry juice treats a urinary tract infection.

Fact: Cranberry products are thought to make a limited contribution to preventing recurrent infections in some women; however, they do not treat an existing infection. Sugary fruit juices can actually irritate the bladder. If you have symptoms, relying on cranberry juice instead of treatment can pave the way for the infection to spread to the kidney.

Is every case of burning when passing urine an infection?

Myth: If it burns when you pass urine, it must be a urinary tract infection.

Fact: Although burning is often caused by an infection, sexually transmitted infections, kidney stones, inflammation of the prostate, vaginal infections and dark urine caused by low fluid intake can also cause burning. For details, see our article on burning when passing urine.

Can you stop antibiotics once the symptoms have gone?

Myth: Stopping the antibiotic once the burning has gone is fine, and antibiotics left over at home can also be used.

Fact: Antibiotics need to be taken for the full recommended course. Incomplete treatment can cause the infection to come back and bacteria to become resistant to medicines. Taking antibiotics left over from a previous illness on your own is not right either; especially with recurrent infections, it is important that treatment is planned according to a urine culture.

Do men get urinary tract infections?

Myth: Urinary tract infections only happen in women.

Fact: They are less common in men, but when they do occur, an underlying cause should usually be looked for. An enlarged prostate, kidney stones, a narrowing of the urethra (urethral stricture) or inflammation of the prostate are among the most common causes. Every urinary tract infection in a man calls for a urological assessment.

How can you prevent urinary tract infections in winter?

1. Drink water without waiting until you feel thirsty. Pale yellow urine is a good sign that you are drinking enough.
2. Do not hold your urine. Make a habit of going to the toilet every 3–4 hours during the day.
3. Empty your bladder completely. Pass urine without rushing, in a comfortable position.
4. Prevent constipation. A high-fibre diet, enough fluids and regular walking keep the bowels regular.
5. Wipe from front to back. In women, wiping from front to back after using the toilet reduces the transfer of bacteria to the urethra.
6. Pass urine after sex.
7. Choose cotton, breathable underwear; do not stay in wet or sweaty clothes for long.
8. Ask before taking cold remedies. If you have an enlarged prostate or have difficulty passing urine, always tell your pharmacist or doctor.
9. Keep your diabetes under control. High blood sugar increases the risk of infection.

For other causes of needing the toilet frequently, you can read our article on the causes of frequent urination.

Why does the risk increase in women after the menopause?

With the menopause, the fall in the hormone oestrogen causes the tissues around the urethra and vagina to become thinner and changes the balance of protective bacteria in this area. For this reason, urinary tract infections can recur more often after the menopause. Conditions such as incomplete bladder emptying, urinary incontinence and prolapse also increase the risk. For women with recurrent infections, local (vaginal) hormone treatments used on a doctor’s advice and other preventive methods are among the options included in guidelines. Whether these treatments are suitable for you is decided after an examination; do not start them on your own.

Which symptoms suggest a kidney infection?

If a bladder infection is not treated, it can spread to the kidney. If you have the following symptoms, seek medical help without waiting:

• A fever of 38 °C or above, shivering
• Pain in the lower back or side (see kidney pain)
• Nausea, vomiting or feeling generally unwell
• Visible blood in the urine (see the causes of blood in the urine)
• Being unable to pass urine at all

In pregnant women, children, people with diabetes and people with a weakened immune system, symptoms of a urinary tract infection should be assessed more quickly.

When should you see a urologist?

A urological assessment is advisable if you have two or more infections in six months or three or more in a year, if you are a man, if your symptoms continue despite treatment, if you see blood in your urine, or if your infections come with kidney stones or a weaker urine flow. For treatment options and the tests carried out for recurrent infections, see the urinary tract infection page. Bringing your previous urine test and culture results with you makes the assessment easier.

Op. Dr. Mücahit Kabar sees patients in Bursa (Nilüfer), Turkey, at Özel Medicabil Nilüfer Hastanesi (weekdays 08:30–12:00, +90 444 8 112) and Özel Jimer Hastanesi (weekdays 13:00–17:00, +90 444 45 67). Appointments are booked through the hospitals’ online booking pages or appointment lines. Consultations are held in English or Turkish; the hospitals’ international patient departments can arrange interpreters for other languages. If you are travelling from abroad, you can send your questions and previous test results by WhatsApp to +90 541 622 54 82 before your visit. See the contact and appointment information for details.