If you can’t pee and feel the urge or pressure to go, start with a few simple physical techniques that can trigger your body’s urination reflex. Most brief episodes resolve on their own, but a complete inability to urinate for several hours, especially with lower abdominal pain or a feeling of fullness, is a medical emergency that can damage your bladder and kidneys.
Techniques to Try Right Now
Sitting in a warm bath is one of the most effective ways to trigger urination. In a study of patients who couldn’t void after surgery, sitting in warm water (about 104°F or 40°C) caused spontaneous urination in 19 out of 21 people. The warm water relaxes the internal sphincter of the urethra through a reflex response, essentially overriding the tension that’s keeping things locked up. If a full bath isn’t practical, running warm water over your lower abdomen or holding a warm, damp towel against your bladder area can produce a milder version of the same effect.
Other techniques worth trying:
- Run water in the sink. The sound of flowing water can stimulate the urination reflex in your brain.
- Lean forward while sitting on the toilet. This increases abdominal pressure on the bladder and can help initiate flow.
- Tap or lightly stroke the skin just below your navel. Gentle stimulation of the lower abdomen can activate the nerves involved in bladder contraction.
- Relax and breathe slowly. Anxiety tightens the pelvic floor. Taking slow, deep breaths and consciously relaxing the muscles between your legs can release the hold.
- Try standing up (if you normally sit) or sitting down (if you normally stand). A change in position sometimes shifts pressure enough to get things started.
Give yourself 10 to 15 minutes with these techniques before escalating your concern. If nothing works and you feel increasing pressure or pain in your lower abdomen, it’s time to get medical help.
When It Becomes an Emergency
Acute urinary retention, the sudden and complete inability to urinate, is a life-threatening condition. If you haven’t been able to void at all for several hours and you feel a painful, swollen lower abdomen, go to an emergency room. The National Institute of Diabetes and Digestive and Kidney Diseases classifies this as requiring immediate care.
The danger isn’t just discomfort. When urine backs up, pressure builds from the bladder into the tubes connecting to the kidneys. Within the first few hours, that pressure reduces the kidneys’ ability to filter blood. After 24 to 48 hours of sustained blockage, blood flow to the kidneys can drop by up to 60%, and the filtering tissue starts to break down. Left untreated, this leads to kidney injury that may not fully reverse.
At the emergency room, the first step is typically a bladder scan, an ultrasound that measures how much urine is trapped. Anything over 400 mL (roughly two cups) is considered diagnostic for urinary retention. A catheter, a thin flexible tube passed through the urethra, is used to drain the bladder immediately and relieve the pressure. This is a brief, uncomfortable procedure but provides fast relief. Once the acute problem is managed, your care team will look into why it happened.
Common Causes in Men
The most frequent cause of urinary retention in men is an enlarged prostate. As the prostate grows (which happens naturally with age), it can squeeze the urethra enough to partially or fully block urine flow. Many men notice a gradual weakening of their stream, difficulty starting, or frequent nighttime trips to the bathroom before an acute episode hits. Certain triggers, like cold weather, alcohol, or a new medication, can push a borderline situation into full retention.
Medications are a major and often overlooked trigger. Drugs with anticholinergic effects can reduce bladder muscle contraction and worsen any existing obstruction. Common culprits include over-the-counter cold and allergy medicines (especially those containing diphenhydramine), certain antidepressants, antipsychotics, and even inhaled medications for COPD. Men with an already-enlarged prostate face nearly five times the risk of acute retention when benign prostatic disease is present. If you recently started a new medication and can’t urinate, mention it immediately to your doctor.
Common Causes in Women
Urinary retention in women is less common but has its own distinct set of causes. The two most frequent are bladder muscle dysfunction and physical obstruction of the urethra. Pelvic organ prolapse, where the bladder, uterus, or rectum drops from its normal position, can kink or pinch the urethra shut. Severe constipation can do the same thing by pressing against the urethra from behind.
Women who have had pelvic surgery, particularly procedures for urinary incontinence like pubovaginal slings, sometimes develop retention as a complication. The sling can press too tightly on the urethra. Uterine fibroids, vaginal infections causing significant swelling, and urethral strictures are other mechanical causes. In rare cases, an imperforate hymen can cause obstructive retention in adolescent girls.
Fowler’s syndrome is a rare condition worth knowing about. It typically appears in young women in their teens or twenties, often triggered by a surgery or illness. The urethral sphincter muscle essentially refuses to relax, trapping urine in the bladder. It’s associated with polycystic ovary syndrome and can be a confusing diagnosis because the women affected are otherwise healthy.
Nerve-Related Causes
Your bladder relies on a complex chain of nerve signals to know when it’s full and to coordinate the muscles that empty it. Damage or disease anywhere along that chain can cause retention. The most common neurological causes include spinal cord injuries, multiple sclerosis, stroke, Parkinson’s disease, and diabetes (which can damage the small nerves controlling the bladder over time).
Herniated discs in the lower back can compress the nerves responsible for bladder function. A particularly serious version of this, called cauda equina syndrome, involves compression of the nerve bundle at the base of the spine. It causes sudden retention along with leg weakness, numbness in the groin area, or loss of bowel control. This is a surgical emergency.
Medications That Can Block Urination
If your retention came on after starting or increasing a medication, the drug itself may be the problem. Several common drug classes reduce the bladder’s ability to contract or increase the tension in the urethral sphincter:
- Antihistamines and cold medicines (diphenhydramine, chlorpheniramine) relax the bladder muscle while tightening the outlet.
- Tricyclic antidepressants have strong anticholinergic effects that slow bladder contractions.
- Antipsychotic medications can impair the nerve signals that coordinate voiding.
- Calcium channel blockers used for blood pressure can reduce bladder muscle tone.
- Opioid pain medications suppress bladder sensation and contraction.
- Decongestants (pseudoephedrine) tighten the smooth muscle around the urethra.
Medication-related retention often resolves once the drug is stopped or adjusted. Never stop a prescription medication on your own, but do flag the timing of your symptoms with your provider so they can evaluate whether a switch makes sense.
What Happens After the First Episode
If you’ve had one episode of acute retention, your medical team will want to figure out why. A post-void residual test (a quick, painless ultrasound after you urinate) measures how much urine remains in the bladder. Under 100 mL is normal. Between 200 and 300 mL suggests your bladder isn’t emptying well. Over 400 mL confirms retention.
Depending on the suspected cause, you may need additional testing: a prostate exam for men, a pelvic exam for women, blood work to check kidney function, or imaging of the urinary tract. For women with pelvic organ prolapse, treating the prolapse typically resolves the retention. For men with an enlarged prostate, medications that relax the prostate or shrink it over time are usually the first line of treatment.
Some people need to use intermittent self-catheterization at home, inserting a small catheter a few times a day to drain the bladder. It sounds daunting, but most people learn the technique quickly and find it far more comfortable than the retention itself. For neurological causes or cases where the bladder muscle has lost function, this may become a long-term management strategy.