While some dietary factors have been associated with prostate cancer the evidence is still tentative. Evidence supports little role for dietary fruits and vegetables in prostate cancer occurrence. Red meat and processed meat also appear to have little effect in human studies. Higher meat consumption has been associated with a higher risk in some studies.

Lower blood levels of vitamin D may increase the risk of developing prostate cancer.

Folic acid supplements have no effect on the risk of developing prostate cancer.

There are also some links between prostate cancer and medications, medical procedures, and medical conditions. Use of the cholesterol-lowering drugs known as the statins may also decrease prostate cancer risk.

Infection or inflammation of the prostate (prostatitis) may increase the chance for prostate cancer while another study shows infection may help prevent prostate cancer by increasing blood flow to the area. In particular, infection with the sexually transmitted infections chlamydia, gonorrhea, or syphilis seems to increase risk. Finally, obesity and elevated blood levels of testosterone may increase the risk for prostate cancer. There is an association between vasectomy and prostate cancer; however, more research is needed to determine if this is a causative relationship.

Research released in May 2007, found that US war veterans who had been exposed to Agent Orange had a 48% increased risk of prostate cancer recurrence following surgery.

Studies indicate that dietary patterns may affect development of BPH, but further research is needed to clarify any important relationship. Studies from China suggest that greater protein intake may be a factor in development of BPH. Men older than 60 in rural areas had very low rates of clinical BPH, while men living in cities and consuming more animal protein had a higher incidence. On the other hand, a study in Japanese-American men in Hawaii found a strong negative association with alcohol intake, but a weak positive association with beef intake. In a large prospective cohort study in the US (the Health Professionals Follow-up Study), investigators reported modest associations between BPH (men with strong symptoms of BPH or surgically confirmed BPH) and total energy and protein, but not fat intake. There is also epidemiological evidence linking BPH with metabolic syndrome (concurrent obesity, impaired glucose metabolism and diabetes, high triglyceride levels, high levels of low-density cholesterol, and hypertension).

Most experts consider androgens (testosterone and related hormones) to play a permissive role in the development of BPH. This means that androgens must be present for BPH to occur, but do not necessarily directly cause the condition. This is supported by evidence suggesting that castrated boys do not develop BPH when they age. In an unusual study of 26 eunuchs from the palace of the Qing dynasty still living in Beijing in 1960, the prostate could not be felt in 81% of the studied eunuchs. The average time since castration was 54 years (range, 41–65 years). On the other hand, some studies suggest that administering exogenous testosterone is not associated with a significant increase in the risk of BPH symptoms, so the role of testosterone in prostate cancer and BPH is still unclear. Further randomized controlled trials with more participants are needed to quantify any risk of giving exogenous testosterone.

Dihydrotestosterone (DHT), a metabolite of testosterone, is a critical mediator of prostatic growth. DHT is synthesized in the prostate from circulating testosterone by the action of the enzyme 5α-reductase, type 2. DHT can act in an autocrine fashion on the stromal cells or in paracrine fashion by diffusing into nearby epithelial cells. In both of these cell types, DHT binds to nuclear androgen receptors and signals the transcription of growth factors that are mitogenic to the epithelial and stromal cells. DHT is ten times more potent than testosterone because it dissociates from the androgen receptor more slowly. The importance of DHT in causing nodular hyperplasia is supported by clinical observations in which an inhibitor of 5α-reductase such as finasteride is given to men with this condition. Therapy with a 5α-reductase inhibitor markedly reduces the DHT content of the prostate and, in turn, reduces prostate volume and BPH symptoms.

Testosterone promotes prostate cell proliferation, but relatively low levels of serum testosterone are found in patients with BPH. One small study has shown that medical castration lowers the serum and prostate hormone levels unevenly, having less effect on testosterone and dihydrotestosterone levels in the prostate.

While there is some evidence that estrogen may play a role in the cause of BPH, this effect appears to be mediated mainly through local conversion of androgens to estrogen in the prostate tissue rather than a direct effect of estrogen itself. In canine "in vivo" studies castration, which significantly reduced androgen levels but left estrogen levels unchanged, caused significant atrophy of the prostate. Studies looking for a correlation between prostatic hyperplasia and serum estrogen levels in humans have generally shown none.

In 2008, Gat et al. published evidence that BPH is caused by failure in the spermatic venous drainage system resulting in increased hydrostatic pressure and local testosterone levels elevated more than 100 fold above serum levels. If confirmed, this mechanism explains why serum androgen levels do not seem to correlate with BPH and why giving exogenous testosterone would not make much difference.

There are several reasons why PIN is the most likely prostate cancer precursor. PIN is more common in men with prostate cancer. High grade PIN can be found in 85 to 100% of radical prostatectomy specimens, nearby or even in connection with prostate cancer. It tends to occur in the peripheral zone of the prostate. With age, it becomes increasingly multifocal, like prostate cancer. Molecular analysis has shown that high grade PIN and prostate cancer share many genetic abnormalities. This has been confirmed in a transgenic mouse model.

The risk for men with high grade PIN of being diagnosed with prostate cancer after repeat biopsy has decreased since the introduction of biopsies at more than six locations (traditional sextant biopsies).

Stones can cause disease by several mechanisms:

- Irritation of nearby tissues, causing pain, swelling, and inflammation

- Obstruction of an opening or duct, interfering with normal flow and disrupting the function of the organ in question

- Predisposition to infection (often due to disruption of normal flow)

A number of important medical conditions are caused by stones:

- Nephrolithiasis (kidney stones)

- Can cause hydronephrosis (swollen kidneys) and renal failure

- Can predispose to pyelonephritis (kidney infections)

- Can progress to urolithiasis

- Urolithiasis (urinary bladder stones)

- Can progress to bladder outlet obstruction

- Cholelithiasis (gallstones)

- Can predispose to cholecystitis (gall bladder infections) and ascending cholangitis (biliary tree infection)

- Can progress to choledocholithiasis (gallstones in the bile duct) and gallstone pancreatitis (inflammation of the pancreas)

- Gastric calculi can cause colic, obstruction, torsion, and necrosis.

In urologic pathology, high-grade prostatic intraepithelial neoplasia, abbreviated HGPIN, is an abnormality of prostatic glands and believed to precede the development of prostate adenocarcinoma (the most common form of prostate cancer).

It may be referred to simply as prostatic intraepithelial neoplasia (abbreviated as PIN). It is considered to be a pre-malignancy, or carcinoma in situ, of the prostatic glands.

The prevalence of salivary stones in the general population is about 1.2% according to post mortem studies, but the prevalence of salivary stones which cause symptoms is about 0.45% in the general population. Sialolithiasis accounts for about 50% of all disease occurring in major salivary glands, and for about 66% of all obstructive salivary gland diseases. Salivary gland stones are twice as common in males as in females. The most common age range in which they occur is between 30 and 60, and they are uncommon in children.

In kidney stones, calcium oxalate is the most common mineral type (see Nephrolithiasis). Uric acid is the second most common mineral type, but an "in vitro" study showed uric acid stones and crystals can promote the formation of calcium oxalate stones.

It is also known that disruption of the endocrine system by certain chemicals adversely affects the development of the reproductive system and can cause vaginal cancer. Many other reproductive diseases have also been link to exposure to synthetic and environmental chemicals. Common chemicals with known links to reproductive disorders include: lead, dioxins and dioxin-like compounds, styrene, toluene, BPA (Bisphenol A) and pesticides.

ASAP is considered an indication for re-biopsy; in one survey of urologists 98% of respondents considered it a sufficient reason to re-biopsy.

There are thought to be a series of stages that lead to the formation of a calculus ("lithogenesis"). Initially, factors such as abnormalities in calcium metabolism, dehydration, reduced salivary flow rate, altered acidity (pH) of saliva caused by oropharyngeal infections, and altered solubility of crystalloids, leading to precipitation of mineral salts, are involved. Other sources state that no systemic abnormality of calcium or phosphate metabolism is responsible.

The next stage involves the formation of a which is successively layered with organic and inorganic material, eventually forming a calcified mass. In about 15-20% of cases the sialolith will not be sufficiently calcified to appear radiopaque on a radiograph, and therefore be difficult to detect.

Other sources suggest a retrograde theory of lithogenesis, where food debris, bacteria or foreign bodies from the mouth enter the ducts of a salivary gland and are trapped by abnormalities in the sphincter mechanism of the duct opening (the papilla), which are reported in 90% of cases. Fragments of bacteria from salivary calculi were reported to be Streptococci species which are part of the normal oral microbiota and are present in dental plaque.

Stone formation occurs most commonly in the submandibular gland for several reasons. The concentration of calcium in saliva produced by the submandibular gland is twice that of the saliva produced by the parotid gland. The submandibular gland saliva is also relatively alkaline and mucous. The submandibular duct (Wharton's duct) is long, meaning that saliva secretions must travel further before being discharged into the mouth. The duct possesses two bends, the first at the posterior border of the mylohyoid muscle and the second near the duct orifice. The flow of saliva from the submandibular gland is often against gravity due to variations in the location of the duct orifice. The orifice itself is smaller than that of the parotid. These factors all promote slowing and stasis of saliva in the submandibular duct, making the formation of an obstruction with subsequent calcification more likely.

Salivary calculi sometimes are associated with other salivary diseases, e.g. sialoliths occur in two thirds of cases of chronic sialadenitis, although obstructive sialadenitis is often a consequence of sialolithiasis. Gout may also cause salivary stones, although in this case they are composed of uric acid crystals rather than the normal composition of salivary stones.

There are two types of prostatic stent: temporary and permanent.

Although a permanent prostatic stent is not a medical treatment, it falls under the classification of a surgical procedure. Placement of a permanent prostatic stent is carried out as an outpatient treatment under local, topical or spinal anesthesia and usually takes about 15–30 minutes.

A temporary prostatic stent can be inserted in a similar manner to a Foley catheter, requiring only topical anesthesia.

In a small minority of cases of urethral syndrome, treatment with antibiotics is effective, which indicates that in some cases it may be caused by bacterial infection which does not show up in either urinalysis or urine culture. For chronic urethral syndrome, a long term, low-dose antibiotic treatment is given on a continuous basis or after intercourse each time if intercourse appears to trigger symptoms.

As low oestrogen may also be considered a source for urethral syndrome, hormone replacement therapy, and oral contraceptive pill (birth-control pills) containing oestrogen are also used to treat the symptoms of this condition in women.

Prostatitis is inflammation of the prostate gland. Prostatitis is classified into acute, chronic, asymptomatic inflammatory prostatitis, and chronic pelvic pain syndrome.

In the United States, prostatitis is diagnosed in 8 percent of all urologist visits and 1 percent of all primary care physician visits.

A prostatic stent is a stent used to keep open the male urethra and allow the passing of urine in cases of prostatic obstruction and lower urinary tract symptoms (LUTS). Prostatic obstruction is a common condition with a variety of causes. Benign prostatic hyperplasia (BPH) is the most common cause, but obstruction may also occur acutely after treatment for BPH such as transurethral needle ablation of the prostate (TUNA), transurethral resection of the prostate (TURP), transurethral microwave thermotherapy (TUMT), prostate cancer or after radiation therapy.

Prostatic secretions escape into the stroma and elicit an inflammatory response.

The main infectious agents are Enterobacteriaceae (such as Escherichia coli and Klebsiella), Neisseria gonorrhoeae and Chlamydia trachomatis.

One study has shown that men with MAGI who have lower serum levels of total testosterone tend to have a more complicated form of MAGI, such as involving more than one site, than those with normal levels.

Signs indicative of urethral syndrome include a history of chronic recurrent urinary tract infections (UTI) in the absence of both conventional bacterial growth and pyuria (more than 5 white blood cells per High Power Field). Episodes are often related to sexual intercourse.

Some physicians believe that urethral syndrome may be due to a low grade infection of the Skene's glands on the sides and bottom of the urethra. The Skene's glands are embryologically related to the prostate gland in the male, thus urethral syndrome may share a comparable cause with chronic prostatitis.

Possible non-infective causes include hormonal imbalance, trauma, allergies, anatomical features such as diverticula, and post-surgical scarring and adhesions.

Examples of congenital abnormalities of the reproductive system include:

- Kallmann syndrome - Genetic disorder causing decreased functioning of the sex hormone-producing glands caused by a deficiency or both testes from the scrotum.

- Androgen insensitivity syndrome - A genetic disorder causing people who are genetically male (i.e. XY chromosome pair) to develop sexually as a female due to an inability to utilize androgen.

- Intersexuality - A person who has genitalia and/or other sexual traits which are not clearly male or female.

Previously, the finding of lymphangitis carcinomatosis meant about a six-month life expectancy. However, improved treatment has improved survival in patients with lymphangitis carcinomatosis, with patients often surviving three or more years with treatment.

Hematospermia, the presence of blood in semen, is most often a benign symptom. Among men age 40 or older, hematospermia is a slight predictor of cancer, typically prostate cancer. No specific cause is found in up to 70% of cases.

On a subsequent biopsy, given the diagnosis of ASAP, the chance of finding prostate adenocarcinoma is approximately 40%; this is higher than if there is high-grade prostatic intraepithelial neoplasia (HGPIN).

Globally, up to 35% of the population over the age of 60 years is estimated to be incontinent.

In 2014, urinary leakage affected between 30% and 40% of people over 65 years of age living in their own homes or apartments in the U.S. Twenty-four percent of older adults in the U.S. have moderate or severe urinary incontinence that should be treated medically.

Bladder control problems have been found to be associated with higher incidence of many other health problems such as obesity and diabetes. Difficulty with bladder control results in higher rates of depression and limited activity levels.

Incontinence is expensive both to individuals in the form of bladder control products and to the health care system and nursing home industry. Injury related to incontinence is a leading cause of admission to assisted living and nursing care facilities. More than 50% of nursing facility admissions are related to incontinence.

Potential complications include:

- obstruction of the epididymis

- impairment of spermatogenesis

- impairmentment of sperm function

- induction of sperm auto-antibodies

- dysfunctions of the male accessory glands

These complications can result in

sexual dysfunction and male subfertility.