Detrusor muscle

Looks like

The thick mesh of smooth muscle making up the bladder wall.

What it does

Relaxes to let the bladder fill and contracts to empty it.

Keeping it well

Overactive, it causes urgency and leaks; underactive, it leaves urine behind. Bladder training helps the first, and being unable to pass urine is an emergency.

Related conditions

• Bedwetting (nocturnal enuresis)
• Benign prostatic hyperplasia
• Bladder cancer
• Bone metastases and spinal cord compression
• Botulism
• Fibromyalgia
• Frailty & falls in older age
• Heat exhaustion & heatstroke
• Interstitial cystitis (bladder pain syndrome)
• Intestinal worms & schistosomiasis
• Malnutrition & refeeding syndrome
• Muscular dystrophy
• Neurogenic bladder
• Obstructed labour and obstetric fistula
• Pelvic organ prolapse
• Polymyalgia rheumatica
• Rhabdomyolysis
• Sarcoma
• Sarcopenia
• Tetanus
• Urinary incontinence
• Urinary tract infection
• Vesicoureteral reflux