Hard flaccid syndrome
| Hard flaccid syndrome | |
|---|---|
| A penis in the "hard flaccid" state | |
| Specialty | Urology, sexual medicine, neurology, men's health |
| Symptoms | A flaccid penis that remains in a firm, semi-rigid state in the absence of sexual arousal |
| Usual onset | Typically following a traumatic event (an injury to the erect penis, blunt perineal trauma, cauda equina) though can also appear without an apparent cause |
| Causes | Excessive sympathetic activity in the erectile smooth muscle tissue |
| Risk factors | Aggressive or prolonged masturbation, rough or prolonged intercourse, practicing penis enlargement techniques, bicycle riding, horseback riding, annular tears, tarlov cysts; other risk factors currently unknown |
| Diagnostic method | Overwhelmingly self-diagnosed |
| Treatment | Definitive treatment does not currently exist |
Hard flaccid syndrome (HFS), also known as hard flaccid (HF), is a rare acquired dysautonomic condition characterized by a flaccid penis that remains in a firm, semi-rigid state in the absence of sexual arousal. Patients often describe their flaccid penis as firm to the touch, rubbery, shrunken, and retracted, frequently accompanied by pain, discomfort, and various other symptoms. While the condition is not fully understood, current research indicates that HFS results from excessive sympathetic nervous system activity in the smooth muscle tissue of the penis, triggered by a pathological activation of a proposed pelvic/pudendal-hypogastric reflex. Among other causes, injuries to the erect penis, blunt trauma to the pelvis or perineum, and damage to the cauda equina are thought to induce this reflex. Although unproven, it is possible that axon sprouting in sympathetic ganglia following a peripheral nerve injury is the true explanation for HFS. The majority of patients are in their 20s and 30s, with symptoms severely affecting their quality of life. Treatment typically involves a combination of alpha blockers and PDE5 inhibitors, although there is limited evidence supporting their efficacy. Due to the lack of comprehensive understanding and awareness within the scientific and medical communities, there is currently no definitive treatment for HFS.