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.

The differential diagnosis of testicular pain is broad and involves conditions from benign to life-threatening. The most common causes of pain in children presenting to the emergency room are testicular torsion (16%), torsion of a testicular appendage (46%), and epididymitis (35%). In adults, the most common cause is epididymitis.

Testicular torsion usually presents with sudden, severe, testicular pain (in groin and lower abdomen) and tenderness. There is often associated nausea and vomiting. The testis may be higher than its normal position. Mild pyrexia and redness of overlying area may be found.

Some of the symptoms are similar to epididymitis though epididymitis may be characterized by discoloration and swelling of the testis, often with fever, while the cremasteric reflex is usually present. Testicular torsion, or more probably impending testicular infarction, can also produce a low-grade fever.

There is often an absent or decreased cremasteric reflex.

Those ages 15 to 35 are most commonly affected. The acute form usually develops over the course of several days, with pain and swelling frequently in only one testis, which will hang low in the scrotum. There will often be a recent history of dysuria or urethral discharge. Fever is also a common symptom. In the chronic version, the patient may have painful point tenderness but may or may not have an irregular epididymis upon palpation, though palpation may reveal an indurated epididymis. A scrotal ultrasound may reveal problems with the epididymis, but such an ultrasound may also show nothing unusual. The majority of patients who present with chronic epididymitis have had symptoms for over five years.

Untreated, acute epididymitis's major complications are abscess formation and testicular infarction. Chronic epididymitis can lead to permanent damage or even destruction of the epididymis and testicle (resulting in infertility and/or hypogonadism), and infection may spread to any other organ or system of the body. Chronic pain is also an associated complication for untreated chronic epididymitis.

A variant is a less serious but chronic condition called intermittent testicular torsion (ITT), characterized by the symptoms of torsion but followed by eventual spontaneous detortion and resolution of pain. Nausea or vomiting may also occur. Though less pressing, such individuals are at significant risk of complete torsion and possible subsequent orchiectomy and the recommended treatment is elective bilateral orchiopexy. Ninety-seven percent of patients who undergo such surgery experience complete relief from their symptoms.

The varicoceles might be noticed as soft lumps, usually above the testicle and mostly on the left side of the scrotum. Right-sided and bilateral varicoceles do also occur. Some people who have them feel pain or heaviness in their scrotum. Varicoceles are sometimes discovered when investigating the cause of male infertility.

Polyorchidism is the incidence of more than two testicles. It is a very rare congenital disorder, with fewer than 201 cases reported in medical literature and 6 cases (two horses, two dogs and two cats) in veterinary literature.

Polyorchidism is generally diagnosed via an ultrasound examination of the testicles. However, the diagnosis of polyorchidism should include histological confirmation. The most common form is triorchidism, or tritestes, where three testicles are present. The condition is usually asymptomatic. A man who has polyorchidism is known as a polyorchid.

Polyorchidism occurs in two primary forms: Type A and Type B.

- Type A: The supernumerary testicle is connected to a vas deferens. These testicles are usually reproductively functional. Type A is further subdivided into:

- Type A1: Complete duplication of the testicle, epididymis and vas deferens.

- Type A2: The supernumerary testicle has its own epididymis and shares a vas deferens.

- Type A3: The supernumerary testicle shares the epididymis and the vas deferens of the other testicles.

- Type B: The supernumerary testicle is not connected to a vas deferens and is therefore not reproductively functional. Type B is further subdivided into:

- Type B1: The supernumerary testicle has its own epididymis but is not connected to a vas deferens

- Type B2: The supernumerary testicle consists only of testicular tissue.

Type A3 is the most common form of polyorchidism, and types A2 and A3 together account for more than 90% of cases. In 65% of cases, the supernumerary testicle is found in the left scrotal sac.

A varicocele is an abnormal enlargement of the pampiniform venous plexus in the scrotum. This plexus of veins drains blood from the testicles. The testicular blood vessels originate in the abdomen and course down through the inguinal canal as part of the spermatic cord on their way to the testis. Varicoceles occur in around 15% of all men.

Spermatocele () is a retention cyst of a tubule of the rete testis or the head of the epididymis distended with barely watery fluid that contains spermatozoa. Small spermatoceles are relatively common, occurring in an estimated 30 percent of all men. They vary in size from several millimeters to many centimeters. Spermatoceles are generally not painful. However, some men may experience discomfort from larger spermatoceles. They are not cancerous, nor do they cause an increased risk of testicular cancer. Additionally, unlike varicoceles, they do not have a negative impact on fertility.

Spermatoceles can be discovered as incidental scrotal masses found on physical examination by a physician. They may also be discovered by self-inspection of the scrotum and testicles.

Finding a painless, cystic mass at the head of the epididymis, that transilluminates and can be clearly differentiated from the testicle, is generally sufficient. If uncertainty exists, ultrasonography of the scrotum can confirm if it is spermatocele.

If an individual finds what he suspects to be a spermatocele, he is advised to consult a urologist.

Post-vasectomy pain syndrome is a chronic and sometimes debilitating genital pain condition that may develop immediately or several years after vasectomy. Because this condition is a syndrome, there is no single treatment method, therefore efforts focus on mitigating/relieving the individual patient's specific pain. When pain in the epididymides is the primary symptom, post-vasectomy pain syndrome is often described as congestive epididymitis.

Any of the aforementioned pain conditions/syndromes can persist for years after vasectomy and affect as many as one in three vasectomized men. The range of PVPS pain can be mild/annoying to the less-likely extreme debilitating pain experienced by a smaller number of sufferers in this group. There is a continuum of pain severity between these two extremes. Pain is thought to be caused by any of the following, either singularly or in combination: testicular backpressure, overfull epididymides, chronic inflammation, fibrosis, sperm granulomas, and nerve entrapment. Pain can be present continuously in the form of orchialgia and/or congestive epididymitis or it can be situational, such as pain during intercourse, ejaculation or physical exertion.

Secondary hydroceles due to testicular diseases can be the result of cancer, trauma (such as a hernia), or orchitis (inflammation of testis), and can also occur in infants undergoing peritoneal dialysis. A hydrocele is not a cancer but it should be excluded clinically if a presence of a testicular tumor is suspected, however, there are no publications in the world literature that report a hydrocele in association with testicular cancer. Secondary hydrocele is most frequently associated with acute or chronic epididymo-orchitis. It is also seen with torsion of the testis and with some testicular tumors. A secondary hydrocele is usually lax and of moderate size: the underlying testis is palpable. A secondary hydrocele subsides when the primary lesion resolves.

- Acute/chronic epididymo-orchitis

- Torsion of testis

- Testicular tumor

- Hematocele

- Filarial hydrocele

- Post herniorrhaphy

- Hydrocele of an hernial sac

The swelling is soft and non-tender, large in size on examination, and the testis cannot usually be felt. The presence of fluid is demonstrated by trans illumination. These hydrocoeles can reach a huge size, containing large amount of fluid, as these are painless and are often ignored. They are otherwise asymptomatic, other than size and weight, causing inconvenience. However the long continued presence of large hydroceles causes atrophy of testis due to compression or by obstructing blood supply. In most cases, the hydrocele, when diagnosed early during complete physical examination, are small and the testis can easily be palpated within a lax hydrocele. However Ultrasound imaging is necessary to visualize the testis if the hydrocele sac is dense to reveal the primary abnormality. But these can become large in cases when left unattended. Hydroceles are usually painless, as are testicular tumors. A common method of diagnosing a hydrocele is by attempting to shine a strong light (transillumination) through the enlarged scrotum. A hydrocele will usually pass light, while a tumor will not (except in the case of a malignancy with reactive hydrocele).

Hypospadias presents as an abnormal location for the end of the urethra which is typically found on the distal end of the penis. It is generally diagnosed at birth from visual confirmation of the hallmark features. As well as an unusual location of the urethra, the prepuce (foreskin) is typically incomplete as well. The abnormal ‘hooded’ prepuce is what often draws attention to the condition but can occur separately to hypospadias.

In Cryptorchidism a diagnosis is made from a physical examination which is performed when the baby is lacking one or both testes in the dependant portion of the scrotal sac. 70% of cryptorchid testes can be felt and are unable to be pulled into the scrotum or retreats quickly after being pulled into a higher position. In 30% of cases the testes cannot be felt indicating an intra-abdominal location. The risk factors for Cryptorchidism are:

- A family history of the condition

- Low birth weight

- Prematurity

90% of ruptured testes are successfully repaired when treated surgically within 72 hours; the percentage of successful treatment drops to 45% after this period. Though not typically fatal, testicular rupture can cause hypogonadism, low self-esteem, and infertility.

Testicular rupture is a rip or tear in the tunica albuginea resulting in extrusion of the testicular contents, including the seminiferous tubules. It is a rare complication of testicular trauma, and can result from blunt or penetrating trauma, though blunt trauma is more likely to cause rupture. Testicular rupture typically results from trauma sustained during a motor vehicle crash or sports play, mainly affects those from the ages of 10-30. The main symptoms of testicular rupture are scrotal swelling and severe pain, which can make diagnosis difficult. Testicular rupture should be suspected whenever blunt trauma to the scrotum has been sustained. Treatment consists of surgical exploration with repair of the injury.

A testicular nubbin is the residual tissue of the human testis after a supposed perinatal vascular accident involving the testicular blood supply. The blood supply of the testis twists (called torsion) thereby cutting off the blood supply to the testis and results in testicular atrophy (shrinking). The nubbin is usually identified in childhood by the absence of a palpable testis in the scrotal sac. The tissue remnant usually includes fibrous tissue and signs of old infarction with hemosiderin deposition identified histologically. There is some disagreement as to whether these should be removed and whether there is a risk of future malignancy. They are typically removed surgically by pediatric urologists or pediatric general surgeons through either a scrotal or inguinal (or both) incision.

Scrotal ultrasonography and transrectal ultrasonography (TRUS) are useful in detecting uni- or bilateral CBAVD, which may be associated with visible abnormalities or agenesis of the epididymis, seminal vesicles or kidneys.

The testicle or testis is the male reproductive gland in all animals, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testosterone. Testosterone release is controlled by the anterior pituitary luteinizing hormone; whereas sperm production is controlled both by the anterior pituitary follicle-stimulating hormone and gonadal testosterone.

Bulbar urethral necrosis is a problem that can occur after a pelvic fracture associated urethral distraction defect (PFUDD).

The vas deferens connect the sperm-producing testicles to the penis. Therefore, those who are missing both vas deferens are typically able to create sperm but are unable to transport them appropriately. Their semen does not contain sperm, a condition known as azoospermia.