A query posted to Reddit, in which a user asked what it meant after a man told her his semen contained “crystals”, has opened a discussion about a common but often silent male health condition: prostatic calculi, or prostate stones.
The social media question prompted a mix of alarm, humour, and shared experience online. Medical experts, however, clarify that the presence of such gritty particles can be a symptom of these well-documented calcium deposits, which form inside the prostate gland and are typically around the size of a poppy seed.
What are prostate stones?
Prostatic calculi are small accumulations of calcium that develop within the prostate. A man may have a single stone or hundreds, and if they are small enough, they can be expelled naturally during urination or ejaculation, potentially leading to the “crystals” described online.
According to Dr Clair Grainger from Superdrug Online Doctor, these stones are often linked to long-term inflammation in the prostate, such as that caused by bacterial prostatitis or chronic pelvic pain conditions. Untreated urinary tract infections can also contribute, as bacteria may become trapped and calcify over time.
The formation process typically involves the blockage of small ducts within the prostate, leading to fluid retention and the precipitation of calcium salts. In other cases, stones can form due to urine refluxing back into the prostatic ducts. Medical literature classifies them into two main types: endogenous (or primary) stones, which form from prostatic secretions and are associated with ageing or inflammation, and exogenous (secondary) stones, which result from urine reflux.
A widespread, often hidden condition
Establishing exactly how common prostate stones are remains difficult for clinicians and researchers. Reported prevalence rates vary extraordinarily widely, from as low as 7% to as high as 70%—and even up to 99% in some specific studies.
This broad range exists primarily because a significant majority of men with the condition experience no symptoms at all. “Most people never know they have prostate stones as they are often only found during a prostate scan,” Dr Grainger explained. They are frequently an incidental discovery during imaging tests like transrectal ultrasound or CT scans conducted for other reasons, such as evaluating benign prostatic hyperplasia (BPH).
Age is a definitive factor. The condition is most prevalent in middle-aged and older men, with incidence rising sharply over the age of 50. Some studies indicate prevalence in approximately one-third of men in their fifties, increasing to around two-thirds of men in their seventies. There is also a strong association with BPH, with studies suggesting between 68.8% and 70% of men with an enlarged prostate also have prostatic calculi.
Symptoms and potential complications
When symptoms do occur, they can affect urinary, sexual, and general pelvic health. Many men remain entirely asymptomatic, but for those who are affected, the presentation can vary.
Dr Grainger notes symptoms can include a dull ache or pressure in the lower pelvis, perineum (the area between the anus and scrotum), or lower back. Research indicates perineal pain affects 15-25% of symptomatic patients, while lower abdominal pain is more common, occurring in 30-40% of cases.
Urinary issues may involve painful urination, difficulty starting or maintaining a stream, increased frequency (especially at night), and a sensation of incomplete emptying. Sexual health can be impacted through stinging pain or discomfort during ejaculation, sometimes accompanied by a weak ejaculation force, reduced semen volume, or changes in its appearance. In some instances, blood may be present in urine or ejaculate.
A key concern for many is fertility. While small, discrete stones may not impair semen quality, larger or more coarse calcifications can be associated with decreased sperm motility. Experts explain that if stones or the associated inflammation spread to the ducts transporting seminal fluid, they can cause partial blockages. This may reduce the quantity and quality of seminal fluid, leading to problems like low sperm count and reduced motility, which can lower conception rates.
Diagnosis and treatment pathways
Medical professionals stress that anyone noticing gritty particles in semen alongside symptoms like pelvic discomfort, painful ejaculation, or urinary problems should consult a GP or urologist. A full STI screening is also advisable to rule out infections like chlamydia or gonorrhoea, which can cause calcification in the reproductive tract if left untreated.
Diagnosis often involves a transrectal ultrasound, though stones may also be identified via CT scan, X-ray, or sometimes felt during a digital rectal examination. Crucially, doctors must differentiate the symptoms from those of other conditions, including prostate cancer, benign prostatic enlargement, chronic prostatitis, kidney stones, or STIs, which can present in similar ways.
Treatment is frequently not required for asymptomatic stones, as the body can sometimes flush them out naturally. “The good news? In most cases, no treatment is required; the body sometimes simply flushes the stones out in urine,” said Dr Grainger.
For symptomatic cases, the approach depends on severity. Conservative management with pain relief or anti-inflammatory drugs may suffice. If the stones act as a source of recurrent infection, a course of antibiotics may be prescribed, though their efficacy can be limited. In cases of severe symptoms, significant blockage, or persistent issues, surgical removal via endoscopic procedures may be necessary. Underlying conditions, particularly BPH, must also be managed, which can involve medications or minimally invasive procedures.