Paraphimosis

Paraphimosis occurs when the foreskin of an uncircumcised or partially circumcised penis is pulled behind the glans and becomes stuck there.

Normally, after the foreskin is retracted, it should be returned over the glans.

If it remains trapped behind the corona, the tight ring of foreskin can restrict normal venous and lymphatic drainage.

The glans and distal foreskin then begin to swell.

As swelling increases, the constriction may become tighter, making the foreskin progressively more difficult to return to its normal position.

Without treatment, arterial circulation may eventually become impaired.

This makes paraphimosis a true urological emergency.

Paraphimosis vs phimosis

These conditions are related but fundamentally different.

Phimosis

The foreskin is too tight to retract normally behind the glans.

Paraphimosis

The foreskin has already been retracted behind the glans but becomes trapped and cannot be returned forward.

Phimosis is generally not an immediate emergency unless it causes severe complications.

Paraphimosis, by contrast, requires urgent treatment because prolonged constriction can compromise blood flow.

Why does the penis swell?

Once the foreskin becomes trapped behind the glans, it forms a tight circumferential band.

This initially obstructs:

• Venous drainage

• Lymphatic drainage

Fluid then accumulates in the glans and foreskin, producing edema.

As swelling increases, the constricting ring becomes even tighter.

In severe or prolonged cases, arterial blood flow can also become compromised.

This can result in:

• Ischemia

• Tissue injury

• Ulceration

• Rarely, necrosis of the glans

Prompt reduction breaks this cycle before permanent injury occurs.

How does paraphimosis usually happen?

One of the most common scenarios is failure to replace the foreskin after it has been retracted for:

• Cleaning

• Physical examination

• Urinary catheter placement

• Cystoscopy

• Another urological procedure

A healthcare professional or caregiver may retract the foreskin and unintentionally leave it behind the glans.

Paraphimosis can also occur after:

• Sexual activity

• Masturbation

• Penile trauma

• Forceful foreskin retraction

Men with underlying phimosis are particularly vulnerable because a tight foreskin is more likely to become trapped once retracted.

Paraphimosis is usually diagnosed clinically.

Laboratory tests or imaging are generally unnecessary.

Medical history

The doctor will ask:

• When the foreskin became trapped

• How long swelling has been present

• Whether symptoms followed catheterization

• Whether the foreskin was retracted for cleaning or examination

• Whether there is underlying phimosis

• Whether previous episodes have occurred

• Whether urination is affected

• Whether severe pain or numbness has developed

Physical examination

Diagnosis is usually obvious on examination.

Typical findings include:

• Retracted foreskin behind the corona

• Tight constricting foreskin band

• Swollen glans

• Swollen distal foreskin

• Inability to manually return the foreskin

The clinician also assesses the color and circulation of the glans.

A pink glans generally suggests preserved blood supply.

Concerning findings include:

• Dusky color

• Blue discoloration

• Pale tissue

• Black discoloration

These may indicate significant ischemia or tissue necrosis.

Assessing urinary function

The doctor may determine whether the patient can urinate normally.

Severe swelling can occasionally interfere with urinary flow.

If a urinary catheter is already present, its position and reason for placement should be reviewed.