Definition
Cystitis is an inflammatory process of the bladder, in most cases caused by a bacterial infection. It is a very common condition in the female population, although it can also affect men. Bladder inflammation may present in acute or chronic form. The acute form generally tends to resolve after a single episode, while the chronic form persists over time, especially in the absence of adequate evaluation and treatment.
Causes
Cystitis is more commonly observed in women because the shorter female urethra facilitates the ascent of microorganisms toward the bladder. Additionally, the reduced anatomic distance between the urethra and anal region further promotes bacterial contamination. The incidence of this condition increases with age and, in many patients, is associated with conditions typical of menopause, such as estrogen reduction and changes in the pelvic floor and organ statics.
In most cases, cystitis has a bacterial origin. The most commonly involved microorganism is Escherichia coli, although other urinary pathogens may also be responsible. Less commonly, bladder inflammation may be related to viral or fungal infections. Unprotected sexual intercourse may also promote infection by transferring bacteria from the genital tract to the urinary tract. Additional associated conditions include the use of certain medications — including immunosuppressants, antineoplastics, corticosteroids, and antibiotics — as well as anatomic or functional abnormalities of the urinary tract that impair normal bladder emptying.
Risk Factors
Tra i principali fattori di rischio rientrano:
- Reduced immune defenses
- Poor intimate hygiene
- Use of tampons or excessively tight underwear and clothing made of synthetic material
- Reduced estrogen production during menopause, which increases the risk of cystitis
- Unprotected sexual intercourse
- Diabetes, as the presence of glucose in urine promotes bacterial proliferation
- Pregnancy, due to possible obstruction of bladder emptying
Symptoms
The most common symptoms of cystitis include frequency, i.e., increased number of voidings during the day, and dysuria, meaning difficulty, burning, or pain during urination. In some cases, bladder tenesmus may also be present, although less frequently. In more severe forms, urine may appear cloudy.
Diagnosis
The diagnosis of cystitis may be made based on the characteristic symptomatology; however, especially in cases of recurrent cystitis, it is essential to identify the cause to establish appropriate treatment.
The clinical interview with the patient represents the first step and allows evaluation of lifestyle habits, associated symptoms, and predisposing factors. Urinalysis combined with urine culture is generally indicated, useful for documenting the presence of bacteria and quantifying the bacterial load. If these tests are negative, vaginal or urethral swabs may be considered. Renal and bladder ultrasound constitutes a second-level investigation, useful for identifying possible incomplete bladder emptying or predisposing conditions, such as urinary calculi, associated with increased frequency of the condition.
Treatment
Treatment of cystitis is generally based on antibiotic therapy. In uncomplicated forms, a short-course oral therapy is sufficient in most cases. In more persistent cases or infections with less susceptible pathogens, antibiotic treatment may require a longer duration.
In addition to prescribed therapy, certain supplements may play a role in reducing the risk of recurrence. Among the most commonly used are products based on hyaluronic acid, D-mannose, cranberry, probiotics, and other compounds used as support in recurrent urinary infections. It is also advisable to maintain good hydration to promote urinary dilution, follow a balanced diet, and limit excess refined sugars and high-salt foods, which may contribute to urinary tract irritation.
Frequently Asked Questions
Cystitis does not resolve in a few hours, although symptoms may begin to diminish within 24-48 hours of starting appropriate antibiotic therapy. In uncomplicated forms, first-line treatments include nitrofurantoin for 5 days, trimethoprim-sulfamethoxazole for 3 days, or fosfomycin as a single dose.
Clinical improvement may appear within the first hours, but the infection requires completion of the entire therapeutic course. Discontinuing therapy prematurely increases the risk of recurrence and development of bacterial resistance.
Rif.: [1, 2]
Drinking at least 1.5 liters of water per day is recommended both during the acute episode and for recurrence prevention. A randomized study showed that increasing daily water intake by 1.5 liters reduces recurrences by approximately 50% in women with recurrent urinary infections.
Hydration promotes urine dilution and contributes to bacterial elimination from the bladder. There is no strong evidence supporting the systematic exclusion of specific foods during cystitis; the main recommendation therefore remains adequate hydration.
Rif.: [3, 4]
Among natural remedies, cranberry has the most consistent scientific support. A Cochrane review comprising 50 studies showed a 30% reduction in the risk of recurrent cystitis in women with repeated episodes (RR 0.74). The mechanism of action is related to proanthocyanidins, which inhibit Escherichia coli adhesion to the urothelium.
D-mannose has also shown favorable results: a meta-analysis reported a 66% reduction in cystitis incidence compared with placebo (RR 0.34), although the overall level of evidence is still limited. For burning control, symptomatic medications such as urinary analgesics or NSAIDs like ibuprofen may be used.
Rif.: [3, 5, 6, 7]
Cystitis is distinguished from vaginal infections primarily on the basis of the clinical picture. It generally presents with dysuria, increased voiding frequency, urinary urgency, and suprapubic pain, in the absence of vaginal discharge. In women presenting these symptoms without vaginal irritation, the probability of cystitis exceeds 90%.
Vaginitis, in contrast, is more often associated with vulvovaginal itching, burning, pathologic leukorrhea, and vaginal odor changes. The presence of vaginal symptoms necessitates diagnostic evaluation oriented toward vaginitis. The flowchart below illustrates the differential diagnostic pathway.
Algoritmo diagnostico per l'approccio alla donna con disuria. Adattato da: Hoffman A, Dolezal KA, Powell R. Dysuria: Evaluation and Differential Diagnosis in Adults. American Family Physician. 2025;111(1):37-46.
Rif.: [8, 9, 10, 11]
Nella cistite ricorrente post-coitale, la profilassi antibiotica assunta dopo il rapporto sessuale rappresenta una strategia efficace. Diversi studi hanno documentato che una singola dose di antibiotico — come trimetoprim-sulfametossazolo, nitrofurantoina o cefalexina — può ridurre in modo significativo il numero delle recidive.
Useful behavioral measures include voiding immediately after intercourse and maintaining adequate hydration. In patients using spermicides, it may be appropriate to evaluate alternative contraceptive methods, as these products may alter the vaginal flora and promote bacterial colonization.
Rif.: [4, 12, 13, 14]
There is no specific evidence absolutely contraindicating the beach or pool during a cystitis episode. However, it is prudent to avoid staying in a wet swimsuit for extended periods, as this may promote bacterial proliferation and local irritation.
During the acute phase, it is reasonable to wait at least 24-48 hours from the start of antibiotic therapy before resuming recreational aquatic activities, to allow the body to respond to treatment and reduce the risk of symptom worsening.
Rif.: [2, 3]
Drinking at least 1.5 liters of water per day is a recommended measure. In women with recurrent cystitis, increasing water intake by approximately 1.5 additional liters per day was associated with a 50% reduction in recurrences.
Water promotes urine dilution and contributes to mechanical bladder flushing, facilitating bacterial elimination before they can adhere to the bladder epithelium and multiply.
Rif.: [3, 4]
The supplements with the most relevant evidence for recurrence prevention are the following:
- →Cranberry: reduces recurrences in women with recurrent cystitis. Most studied dosage: 36 mg PAC per day.
- →D-mannose: has shown efficacy in prevention, although evidence is not yet definitive. Typical dosage: 1-2 grams per day.
- →Probiotics (Lactobacillus): may be useful especially in combination with other preventive interventions.
- →Methenamine hippurate: has proven effective in preventing recurrent cystitis in recent studies.
- →Vitamin C: often combined with other supplements; evidence supporting it as a single agent remains limited.
It is important to emphasize that these supplements are indicated primarily for recurrence prevention and not for the treatment of the acute episode, which requires appropriate antibiotic therapy.
Rif.: [1, 3, 5, 6, 7, 15, 16]
For information on gynecologic examination and the initial diagnostic pathway, visit the portal dedicated to clinical gynecology.
iltuoginecologo.it → Clinical Gynecology
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