Cystitis: what helps fast, when antibiotics are needed and when to see a doctor

How to recognise a bladder infection

The typical signs are burning when passing urine, a constant urge to urinate with small amounts, pressure or pain above the pubic bone and cloudy, strong-smelling urine, sometimes with a little blood. Fever is not part of it. If these symptoms occur in a woman without discharge and without itching, according to Hooton’s review in the New England Journal of Medicine the probability of cystitis is above 90 percent. A urine dipstick can support the assessment but is not necessary in uncomplicated cases; a urine culture is reserved for when treatment fails, infections recur or risk factors exist.

The cause is almost always gut bacteria ascending through the short female urethra into the bladder. Flores-Mireles and colleagues describe in Nature Reviews Microbiology that Escherichia coli is responsible for around three quarters of uncomplicated infections, followed by Klebsiella, Staphylococcus saprophyticus and enterococci. Every second woman experiences at least one bladder infection in her life; in 20 to 30 percent it comes back.

Uncomplicated or complicated? This distinction decides everything that follows. Uncomplicated means: woman, not pregnant, no malformation or functional disorder of the urinary tract, no catheter, no relevant kidney or immune disease, no poorly controlled diabetes, no signs of kidney involvement. Everything else, including every bladder infection in a man, counts as complicated and needs examination and urine culture.

What helps immediately

Three measures work regardless of whether an antibiotic is added later:

• Drinking. Two to three litres spread over the day so that the bladder is flushed frequently and bacteria have less time to attach to the bladder wall. Do not suppress the urge to urinate.
• Warmth. A hot water bottle on the lower abdomen relaxes the bladder muscle and relieves cramps.
• Ibuprofen. 400 mg up to three times a day (not with stomach ulcers, kidney impairment or in late pregnancy) reduces pain and inflammation. Paracetamol is an alternative but less anti-inflammatory.

It is better to avoid alcohol, coffee and heavily sweetened drinks, which irritate the bladder. Bladder teas with bearberry leaves have weak evidence and are not intended for long-term use. A day of rest helps but is not a condition.

Antibiotic or wait?

The trial by Gágyor and colleagues in the BMJ in 2015 answered this question precisely. 494 women with uncomplicated cystitis received either ibuprofen or the antibiotic fosfomycin. Two thirds of the ibuprofen group recovered without antibiotics. In return they had symptoms that were on average one day longer and more severe, and five women developed a kidney infection compared with one in the fosfomycin group.

The S3 guideline of the German Society of Urology draws a balanced rule from this: for mild to moderate symptoms, purely symptomatic treatment can be offered if the patient wants this after being informed and has no risk factors. For severe symptoms, blood in the urine, symptoms for more than two days, known tendency to recurrence or risk factors, the antibiotic is the better choice. It usually works within 24 to 48 hours.

First choice are substances that act mainly in the urinary tract and disturb the gut flora little:

Substance	Dosing	Notes
Fosfomycin trometamol	3 g once, in the evening after urinating	Convenient, well tolerated, effect assessable after 2 to 3 days
Nitrofurantoin	100 mg twice daily for 5 days	Not with impaired kidney function, not in the last month of pregnancy
Pivmecillinam	400 mg three times daily for 3 days	Can also be used in pregnancy
Nitroxoline	250 mg three times daily for 5 days	Alternative in case of intolerance
Trimethoprim	200 mg twice daily for 3 days	Only where local resistance rates are below 20 percent

Fluoroquinolones such as ciprofloxacin and cephalosporins are not first choice for uncomplicated cystitis: they promote resistance and, in the case of fluoroquinolones, have rare but serious side effects on tendons, nerves and blood vessels. The choice in each case depends on allergies, previous treatments, pregnancy and kidney function.

Why the video consultation fits well here

Uncomplicated cystitis is one of the few conditions for which guidelines allow treatment based on symptoms alone. The conversation provides the decisive information: type and duration of symptoms, fever, flank pain, discharge, pregnancy, pre-existing conditions, previous infections and antibiotics, allergies. In the typical case a physical examination adds no further certainty. That is why the doctor at OpenClinic24 can issue a private prescription after the video consultation if an antibiotic makes sense, or agree symptomatic treatment with you.

The limit is clear: as soon as fever, flank pain, pregnancy, male sex, catheter, known urinary tract malformations, kidney disease or poorly controlled diabetes are involved, an examination with urine culture is needed. Then the doctor refers you to a practice or, if you feel very unwell, to the out-of-hours service.

If it does not get better

If symptoms do not improve after 48 hours on antibiotics or return within two weeks, a urine culture is needed to determine the pathogen and its sensitivity. Possible reasons: a resistant organism, a different pathogen, kidney involvement or an entirely different cause of the symptoms, such as a vaginal infection, an overactive bladder or interstitial cystitis. Blood in the urine that persists after treatment must be assessed by a urologist.

Preventing recurrences: what is actually proven

Recurrent bladder infections, defined as at least two in six or three in twelve months, affect every fourth to fifth woman after a first infection. The evidence for prevention varies in strength:

• Drinking. In a randomised trial in JAMA Internal Medicine, the number of infections halved in women who drank an additional 1.5 litres of water a day. This is the simplest and best-supported measure.
• Behaviour. Pass urine after intercourse, avoid spermicides and diaphragms, wipe from front to back. The evidence is weaker, the risk zero.
• Local oestrogen after menopause restores the protective vaginal flora and significantly lowers the infection rate; it is applied as cream or pessary and hardly absorbed into the blood.
• Methenamine hippurate was non-inferior to continuous antibiotic prophylaxis in the ALTAR trial in the BMJ 2022 and avoids resistance.
• Cranberry moderately reduces recurrent infections according to the 2023 Cochrane analysis; the effect depends on product and dose.
• D-mannose showed no advantage over placebo in a large British trial in 2024.
• Antibiotic prophylaxis, continuous or after intercourse, is effective but the last resort because of resistance.
• Immunoprophylaxis with an extract of E. coli components reduces recurrences in studies by about a third.

Anyone with more than three infections a year should have a urological or gynaecological assessment to check for residual urine, stones, prolapse or another cause.

Special situations

Pregnancy. Here every bacteriuria is treated, even without symptoms, because the risk of kidney infection and premature birth rises. Needed are urine culture, an antibiotic approved in pregnancy and a check after treatment. Care belongs with the gynaecologist; the video consultation can establish first contact but does not replace the examination.

Men. A bladder infection is rare and usually an expression of prostate or urethral involvement. Examination, urine culture and a longer course are standard.

Older people. Confusion or falls may be the only sign; conversely, bacteria in the urine without symptoms are common in older people and are not treated.

Children. Fever without an apparent cause can be a urinary tract infection; children belong with a paediatrician.

Cystitis and work

One to three days of rest are reasonable with severe symptoms, especially if frequent urination makes work impossible. The doctor can issue a sick note in the video consultation if it is medically justified. How long incapacity for work is usual for various conditions is explained in the article on the duration of sick notes.