These patients have no history of genitourinary pain complaints, but leukocytosis is noted, usually during evaluation for other conditions.

Diagnosis is through tests of semen, expressed prostatic secretion (EPS) or prostate tissue that reveal inflammation in the absence of symptoms.

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.

Men with acute prostatitis often have chills, fever, pain in the lower back, perineum, or genital area, urinary frequency and urgency often at night, burning or painful urination, body aches, and a demonstrable infection of the urinary tract, as evidenced by white blood cells and bacteria in the urine. Acute prostatitis may be a complication of prostate biopsy. Often, the prostate gland is very tender to palpation through the rectum.

Chronic bacterial prostatitis is a relatively rare condition that usually presents with an intermittent UTI-type picture. It is defined as recurrent urinary tract infections in men originating from a chronic infection in the prostate. Symptoms may be completely absent until there is also bladder infection, and the most troublesome problem is usually recurrent cystitis.

Chronic bacterial prostatitis occurs in less than 5% of patients with prostate-related non-BPH lower urinary tract symptoms (LUTS).

Dr. Weidner, Professor of Medicine, Department of Urology, University of Gießen, has stated: "In studies of 656 men, we seldom found chronic bacterial prostatitis. It is truly a rare disease. Most of those were E-coli."

The term "prostatitis" refers, in its strictest sense, to histological (microscopic) inflammation of the tissue of the prostate gland. Like all forms of inflammation, it can be associated with an appropriate response of the body to an infection, but it also occurs in the absence of infection.

In 1999, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) devised a new classification system. For more specifics about each type of prostatitis, including information on symptoms, treatment, and prognosis, follow the links to the relevant full articles.

In 1968, Meares and Stamey determined a classification technique based upon the culturing of bacteria. This classification is no longer used.

The conditions are distinguished by the different presentation of pain, white blood cells (WBCs) in the urine, duration of symptoms and bacteria cultured from the urine. To help express prostatic secretions that may contain WBCs and bacteria, prostate massage is sometimes used.

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is characterized by pelvic or perineal pain without evidence of urinary tract infection, lasting longer than 3 months, as the key symptom. Symptoms may wax and wane. Pain can range from mild to debilitating. Pain may radiate to the back and rectum, making sitting uncomfortable. Pain can be present in the perineum, testicles, tip of penis, pubic or bladder area. Dysuria, arthralgia, myalgia, unexplained fatigue, abdominal pain, constant burning pain in the penis, and frequency may all be present. Frequent urination and increased urgency may suggest interstitial cystitis (inflammation centred in bladder rather than prostate). Post-ejaculatory pain, mediated by nerves and muscles, is a hallmark of the condition, and serves to distinguish CP/CPPS patients from men with BPH or normal men. Some patients report low libido, sexual dysfunction and erectile difficulties.

Acute prostatitis is relatively easy to diagnose due to its symptoms that suggest infection. The organism may be found in blood or urine, and sometimes in both. Common bacteria are "Escherichia coli, Klebsiella, Proteus, Pseudomonas, Enterobacter, Enterococcus, Serratia," and "Staphylococcus aureus." This can be a medical emergency in some patients and hospitalization with intravenous antibiotics may be required. A complete blood count reveals increased white blood cells. Sepsis from prostatitis is very rare, but may occur in immunocompromised patients; high fever and malaise generally prompt blood cultures, which are often positive in sepsis. A prostate massage should never be done in a patient with suspected acute prostatitis, since it may induce sepsis. Since bacteria causing the prostatitis is easily recoverable from the urine, prostate massage is not required to make the diagnosis. Rectal palpation usually reveals an enlarged, exquisitely tender, swollen prostate gland, which is firm, warm, and, occasionally, irregular to the touch. C-reactive protein is elevated in most cases.

Prostate biopsies are not indicated as the (clinical) features (described above) are diagnostic. The histologic correlate of acute prostatitis is a neutrophilic infiltration of the prostate gland.

Acute prostatitis is associated with a transiently elevated PSA, i.e., the PSA is increased during an episode of acute prostatitis and then decreases again after it has resolved. PSA testing is not indicated in the context of uncomplicated acute prostatitis.

Chronic bacterial prostatitis is a bacterial infection of the prostate gland. It should be distinguished from other forms of prostatitis such as acute bacterial prostatitis and chronic pelvic pain syndrome (CPPS).

Chronic nonbacterial prostatitis or chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a pelvic pain condition in men, and should be distinguished from other forms of prostatitis such as chronic bacterial prostatitis and acute bacterial prostatitis. This condition was formerly known as prostatodynia (painful prostate). CP/CPPS and interstitial cystitis are sometimes referred to jointly as "UCPPS" (urologic chronic pelvic pain syndrome).

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

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.

Urethral syndrome is characterised by a set of symptoms typically associated with lower urinary tract infection, such as painful urination (dysuria) and frequency. It is a diagnosis of exclusion, made when there is no significant presence of bacteriuria with a conventional pathogen ruling out urinary tract infection, and when cystoscopy shows no inflammation of the bladder, ruling out interstitial cystitis and cystitis cystica. In women, vaginitus should also be ruled out.

Granulomatous prostatitis is an uncommon disease of the prostate, an exocrine gland of the male reproductive system. It is a form of prostatitis, i.e. inflammation of the prostate, resulting from infection (bacterial, viral, or fungal), the BCG therapy, malacoplakia or systemic granulomatous diseases which involve the prostate.

Lower urinary tract infection is also referred to as a bladder infection. The most common symptoms are burning with urination and having to urinate frequently (or an urge to urinate) in the absence of vaginal discharge and significant pain. These symptoms may vary from mild to severe and in healthy women last an average of six days. Some pain above the pubic bone or in the lower back may be present. People experiencing an upper urinary tract infection, or pyelonephritis, may experience flank pain, fever, or nausea and vomiting in addition to the classic symptoms of a lower urinary tract infection. Rarely the urine may appear bloody or contain visible pus in the urine.

In young children, the only symptom of a urinary tract infection (UTI) may be a fever. Because of the lack of more obvious symptoms, when females under the age of two or uncircumcised males less than a year exhibit a fever, a culture of the urine is recommended by many medical associations. Infants may feed poorly, vomit, sleep more, or show signs of jaundice. In older children, new onset urinary incontinence (loss of bladder control) may occur.

Several case studies on IgG4-related prostatitis have been reported. Patients have been noted to commonly present with lower urinary tract symptoms such as dysuria, pollakisuria, urinary urgency, and a feeling of incomplete emptying. The clinical presentation is similar to that in benign prostatic hyperplasia or chronic prostatitis, although pain, as occurs in CP/CPPS, does not usually appear to be significant.

Epididymitis occurs when there is inflammation of the epididymis (a curved structure at the back of the testicle). This condition usually presents with gradual onset of varying degrees of pain, and the scrotum may be red, warm and swollen. It is often accompanied by symptoms of a urinary tract infection, fever, and in over half of cases it presents in combination with orchitis. In those between the ages of 14 to 35 it is usually caused by either gonorrhea or chlamydia. In people either older or younger E. coli is the most common bacterial infection. Treatment involves the use of antibiotics.

Men with IgG4-related prostatitis may have similar findings to those that are frequently, but not always, seen in other organ manifestations of IgG4-related disease, such as elevated blood levels of IgG4, IgE and eosinophils.

FDG-PET scans have been reported to be useful as a diagnostic modality for detecting IgG4-related prostatitis in men with IgG4-RD.

Testicular torsion usually presents with an acute onset of diffuse testicular pain and tenderness of less than 6 hrs of duration. There is often an absent or decreased cremasteric reflex, the testicle is elevated, and often is horizontal. It occurs annually in about 1 in 4000 males before 25 years of age, is most frequent among adolescents ( 65% of cases presenting between 12 – 18 years of age ), and is rare after 35 years of age. Because it can lead to necrosis within a few hours, it is considered a surgical emergency. Another version of this condition is a chronic illness called intermittent testicular torsion (ITT) which is characterized by recurrent rapid acute onset of pain in one testis which will temporarily assume a horizontal or elevated position in the scrotum similar to that of a full torsion followed by eventual spontaneous detortion and rapid solution of pain. Nausea or vomiting may also occur.

Signs and symptoms of acute pyelonephritis generally develop rapidly over a few hours or a day. It can cause high fever, pain on passing urine, and abdominal pain that radiates along the flank towards the back. There is often associated vomiting.

Chronic pyelonephritis causes persistent flank or abdominal pain, signs of infection (fever, unintentional weight loss, malaise, decreased appetite), lower urinary tract symptoms and blood in the urine. Chronic pyelonephritis can in addition cause fever of unknown origin. Furthermore, inflammation-related proteins can accumulate in organs and cause the condition AA amyloidosis.

Physical examination may reveal fever and tenderness at the costovertebral angle on the affected side.

Pyelonephritis that has progressed to urosepsis may be accompanied by signs of septic shock, including rapid breathing, decreased blood pressure, shivering, and occasionally delirium.

The most common symptoms of IC/BPS are suprapubic pain, urinary frequency, painful sexual intercourse, and waking up from sleep to urinate.

In general, symptoms may include painful urination described as a burning sensation in the urethra during urination, pelvic pain that is worsened with the consumption of certain foods or drinks, urinary urgency, and pressure in the bladder or pelvis. Other frequently described symptoms are urinary hesitancy (needing to wait for the urinary stream to begin, often caused by pelvic floor dysfunction and tension), and discomfort and difficulty driving, working, exercising, or traveling. Pelvic pain experienced by those with IC typically worsens with filling of the urinary bladder and may improve with urination.

During cystoscopy, 5–10% of people with IC are found to have Hunner's ulcers. A person with IC may have discomfort only in the urethra, while another might struggle with pain in the entire pelvis. Interstitial cystitis symptoms usually fall into one of two patterns: significant suprapubic pain with little frequency or a lesser amount of suprapubic pain but with increased urinary frequency.

Women with aerobic vaginitis usually present with a thinned reddish vaginal mucosa, sometimes with extensive erosions or ulcerations and abundant yellowish discharge (without the fishy amine odour, typical of bacterial vaginosis). The pH is usually high. Symptoms can include burning, stinging and dyspareunia. The symptoms can last for long periods of time—sometimes even years. Typically, patients have been treated several times with antimycotic and antibiotic drugs without relief. In asymptomatic cases, there is microscopic evidence but no symptoms. The prevalence of asymptomatic cases is unknown.

MAGI includes infections (bacterial, viral, fungal etc) involving one or more of the following male genital organs or tracts:

- seminal vesicles (seminal vesiculitis)

- prostate gland (prostatitis)

- vas deferens

- epididymis (epididymitis)

- testicles (orchitis)

- urethra (urethritis)

- Cowper's glands

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.