Cystitis: inflammation of the bladder
How the urothelium and regular emptying keep the bladder sterile, how E. coli overcomes them, and how drugs, radiation, viruses, allergy, mycobacteria, faulty macrophages and schistosome eggs each inflame the bladder in their own way.
By the end, you can
- Describe the urothelium, its glycosaminoglycan layer and the other defences that keep bladder urine sterile.
- Explain how uropathogenic E. coli adheres to and invades the urothelium, and why bacterial cystitis is much commoner in women.
- Relate haemorrhagic cystitis to its causes: acrolein from cyclophosphamide and ifosfamide, viruses and pelvic radiation.
- Explain interstitial cystitis/bladder pain syndrome, eosinophilic and granulomatous cystitis (including BCG) and malakoplakia by their mechanisms.
- Explain how Schistosoma haematobium eggs inflame, scar and calcify the bladder wall, setting the scene for squamous carcinoma.
- Recognise the classic appearances and tests of each form, and explain how the main treatments act on its mechanism.
What it is
Cystitis is inflammation of the urinary bladder. Most is acute bacterial cystitis, infection of the lining by gut bacteria that have climbed the urethra. Other forms are named by cause or appearance: haemorrhagic (drugs, viruses, radiation), interstitial cystitis/bladder pain syndrome, eosinophilic, granulomatous (tuberculosis, BCG), malakoplakia and schistosomal cystitis. All share the same irritative symptoms, because an inflamed lining and wall make the bladder’s sensory nerves signal urgency and pain.
5 types to tell apart
- Acute bacterial cystitis
- Infection of the bladder lining, usually by E. coli; uncomplicated in a healthy, non-pregnant woman with a normal urinary tract, complicated otherwise.
- Haemorrhagic cystitis
- Cystitis with visible bleeding, from acrolein (cyclophosphamide, ifosfamide), viruses in immunosuppressed people (BK virus, adenovirus) or pelvic radiation.
- Interstitial cystitis/bladder pain syndrome
- Chronic bladder pain with filling and frequency, without infection; with or without Hunner lesions.
- Eosinophilic, granulomatous cystitis and malakoplakia
- Inflammation dominated by eosinophils (allergy, drugs), by granulomas (tuberculosis, BCG, previous surgery) or by macrophages that cannot digest bacteria.
- Schistosomal cystitis
- Chronic granulomatous inflammation round Schistosoma haematobium eggs trapped in the bladder wall, with fibrosis and calcification.
US spelling: haemorrhagic → hemorrhagic, sulphate → sulfate.
Normal function
How the bladder lining keeps urine out and bacteria off
The bladder is lined by urothelium (transitional epithelium): rounded under a surface layer of large . Umbrella cells are sealed together by tight junctions, and their surface membrane is stiffened by plates of uroplakin proteins. Over them lies a hydrated layer of glycosaminoglycans (GAG), including chondroitin sulphate. Together they make the lining almost impermeable, so urea, potassium and acid in urine cannot reach the below, with its and nerves, or the detrusor muscle beyond it.
The main defence against infection is flow: regular, complete emptying washes out bacteria before they can multiply. Acidic, concentrated urine slows their growth; uromodulin (Tamm–Horsfall protein), made by the kidney, coats bacterial fimbriae and acts as a decoy; infected umbrella cells are shed with their bacteria; and the urethra itself is a barrier, longer in men.
Sensory nerves in the wall signal stretch as the bladder fills. Inflammation sensitises them, so a small volume feels urgent and voiding burns: the frequency, urgency, painful voiding and suprapubic pain common to every form of cystitis.
Underlying change · Step 1 of 5
Bacterial cystitis: E. coli grips, invades and hides
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Underlying change · Step 2 of 5
Haemorrhagic cystitis: acrolein, viruses and radiation
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 3 of 5
Interstitial cystitis/bladder pain syndrome
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 4 of 5
Eosinophilic and granulomatous cystitis, and malakoplakia
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Consequences · Step 5 of 5
Schistosomal cystitis: eggs, granulomas and a calcified bladder
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Symptoms and signs
Symptoms, signs and findings
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Exam detail
Exam detail
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Treatment
How treatment works
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Recap
Recap
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Self-check
Check your understanding
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .