URINARY URGENCY: PHYSIOLOGY, CAUSES, TREATMENT - MEDICINE - 2025

The urgency is an urgent need to urinate, occurring repeatedly, even if the bladder is empty. It is a symptom that is related to the voluntary effort when perceiving bladder fullness, feeling the need to urinate.

Urinary urgency accompanies other symptoms of urinary disorders. Frequency and dysuria, which involve pain and difficulty in urination, are some associated symptoms.

It is important not to confuse tenesmus with urgency; the urgency occurs when the bladder is full of urine, prompting the person to urinate immediately when they feel they cannot contain themselves.

Urinary urgency is a nonspecific symptom that basically consists of various reflex mechanisms involved, which initiate contractions of the bladder smooth muscle, promoting the appearance of urgency, with multiple causes. Symptomatic treatment will provide relief from urgency, but there may be recurrences.

A proper diagnosis of the causes, and the establishment of a treatment for them will determine the definitive elimination of the annoying symptom.

Anatomy and physiology

The pathophysiological mechanism of tenesmus requires an understanding of its anatomy and physiology.

Anatomical description

The urinary bladder is a predominantly muscular organ behind the pubis; It has elastic properties that allow it to widen, its function being to contain urine.

The bladder muscle is called the detrusor, with relaxation and contraction functions, involved in its filling and emptying.

A triangular space located in the wall of the bladder, called the trigone, corresponds to the mouth of the ureters that carry urine from the kidneys to the urinary sphincter. Beyond the sphincter, the urinary tract continues with the urethra in charge of carrying urine to the outside.

The detrusor and the bladder sphincter have opposite and coordinated actions: the relaxation of one implies the contraction of the other.

Physiology

Urination has voluntary and involuntary components: the first is conscious, allowing it to be held for emptying the bladder, through voluntary action on the bladder sphincter.

The involuntary component of urination is determined by the autonomic nervous system: the sympathetic innervation dependent on the hypogastric nerve plexus and the parasympathetic innervation established by the sacral plexus. Both nervous systems are simultaneously coordinating the filling and emptying phases of the bladder.

Both the actions of the different muscle groups related to urination and the reflexes that allow this physiological act have been extensively studied, a total of twelve reflexes being described so far.

Urination requires the coordinated action of receptors in the bladder wall, autonomic nerves, and central nervous system. The receptors in the wall will pick up the product tension of a full bladder, or relaxation after emptying.

The stimulus travels through the afferent pathway to the pontine micturition center (CPM) to coordinate the voiding reflex; the effector response will produce the desire to urinate. The CPM is located in the medulla oblongata, but a structure called the locus coereleus is believed to be involved as well.

The corresponding effector response will then be:

1. Full bladder: detrusor contraction and sphincter relaxation;
2. Empty bladder: detrusor relaxation and onset of filling, with sphincter contraction.

Mechanisms of urination

There are three mechanisms on which urination depends:

• Involuntary motor: cause of detrusor contraction.
• Voluntary motor: contraction of abdominal muscles and sphincter control.
• Sensory mechanism: afferent and efferent nerve impulse that produces the voiding response.

Pathophysiology

The induced response produced by tenesmus is somewhat complex, involving multiple receptors and effectors; however it can be explained in a simple way.

Any stimulus capable of producing inflammation of bladder structures can produce the voiding reflex or urgency. The same happens with compression of bladder structures or the presence of foreign bodies inside.

As the bladder wall is stimulated, the impulse travels to the CPM, and is interpreted as a full bladder. The response sent to the bladder will produce the characteristic sensation of urgency.

This is how tenesmus is a sensory symptom, dependent on an irritating stimulus from the bladder, the consequence of which is an annoying and repeated sensation.

Causes

Urinary urgency is a symptom related to multiple causes. Infections are the most common cause of urinary symptoms, including tenesmus; other factors such as the presence of foreign bodies, tumors or inflammation can also cause it.

A fairly precise approach to the causes of urgency appears in a consensus of experts in palliative care. This consensus classifies the causes of tenesmus according to its origin into 6 groups:

Infections

-Bacterial, including STIs, cystitis, urethritis, or vaginitis caused by bacteria.

-Fungal, as in the case of Candida albicans candidiasis.

-Virals, such as those produced by herpes-type viruses (Herpes simplex).

Anatomical causes

-Pelvic tumors.

-Cystocele (protrusion of the bladder).

-Urinary obstruction or urethral stricture.

Inflammatory causes

-Amyloid.

-Radiotherapy and Chemotherapy, the latter induced by the use of Cyclophosphamide.

-Idiopathic cystitis.

-Reaction to foreign body.

Bladder instability

-Primary or idiopathic bladder spasm.

-Secondary bladder spasm, such as contractions due to catheters or blood clots.

Neoplasms

-Cancer of the bladder, urethra or any pelvic organ.

Strange bodies

-Catheters or urinary catheters

-Urinary bladder stones.

Other

-Hypersensitivity reactions.

-Female pelvic disorders, including pelvic inflammatory disease.

Treatment

The treatment of urinary urgency should be aimed at improving the symptom, as well as suppressing the original causes. The treatments used, in some cases, may be common to those used for other urinary symptoms.

Among the most used treatments for symptomatic relief are:

Antispasmodics

Its effect is antispasmodic relaxant of visceral smooth muscles.

• Hyoscine
• Flavoxate, selective lower urinary tract spasmolytic.

Analgesics and non-steroidal anti-inflammatory drugs (NSAIDs)

They work by inhibiting inflammatory and pain mediators.

• Ibuprofen
• Diclofenac
• Ketoprofen
• Ketorolac

Steroids

Its effect is clearly anti-inflammatory, thus achieving symptomatic relief

• Prednisone
• Deflazacort

Local anesthetics

Used locally, either in gel, creams or by local instillation.

• Xylocaine (whose presentation can be in gel for local use).
• Lidocaine.
• Bupivacaine.

Tricyclic antidepressants

Although a side effect of tricyclic antidepressants can be acute urinary retention, they are often helpful in chronic urinary symptoms.

• Amitriptyline
• Imipramine

Warnings

The mention of these drugs is referential, and they should only be used under indication and strict medical supervision.

A proper diagnosis will determine the causes of urinary urgency and its treatment.

Treatment of the causes of urinary symptoms, including urgency, is important to prevent recurrence of these.

References

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