By Dr. Oliver Pack (Medical Doctor – Reg. No. 030308944).
Among the conditions that can affect male fertility is orchitis, especially when it is associated with viral infections such as mumps or with severe inflammatory processes. This condition does not always leave lasting effects, but its impact can be significant when it is severe or affects both testicles.
Orchitis is an inflammation of the testicle that can appear suddenly and cause pain, swelling, or tenderness in the scrotum. It is usually caused by an infection, although it can sometimes be associated with trauma or with the spread of a previous inflammation of the epididymis, known as epididymo-orchitis. Depending on the cause, it may affect one testicle or occur bilaterally, which increases the risk of complications.
Male fertility can be compromised by different conditions that, in many cases, require minimally invasive treatment or even simple lifestyle changes. For this reason, proper monitoring of testicular health is very important in order to detect these types of problems early.
Orchitis is a testicular inflammation that usually manifests with clear symptoms and, in some cases, can have long-term consequences if not treated properly.
In most cases, the clinical picture begins with:

There are several possible causes of orchitis in men. One is bacterial in origin, usually related to genitourinary infections or sexually transmitted infections. Another cause is viral, with mumps being the most well-known, especially when the infection occurs during adolescence or adulthood.
This type of viral inflammation tends to be more aggressive and can cause more severe damage to testicular tissue. There are also cases secondary to trauma or medical procedures, although these are less common.
To diagnose orchitis, a physical examination is usually sufficient, along with some complementary tests to differentiate it from other conditions, such as testicular torsion. Diagnosis is typically confirmed by scrotal ultrasound, which allows evaluation of the testicular tissue and detection of signs of inflammation, fluid accumulation, or altered blood flow.
In parallel, blood and urine tests help identify the infectious cause and guide treatment.
As with other conditions affecting the genital area in both men and women, the impact on fertility largely depends on the severity of the inflammation and the type of infection causing it. If the condition is mild or unilateral, it usually does not leave significant long-term effects. However, if the inflammation is severe or affects both testicles, it can damage the cells responsible for sperm production and reduce sperm concentration, motility, or morphology.
Mumps-related orchitis, especially when it develops after puberty, is the type most frequently associated with long-term impairment of semen quality. The inflammation can compromise both hormone production and spermatogenesis, leading in some men to severe oligozoospermia or even azoospermia.

On the other hand, bacterial orchitis usually responds quickly to antibiotic treatment and, although it may temporarily affect sperm parameters, testicular function typically recovers over time. Viral orchitis, however, tends to be more aggressive, as viruses have a greater capacity to destroy testicular tissue.
In any case, testicular inflammation alters the environment in which sperm are produced. Increased temperature, pressure within the seminiferous tubules, and damage to germ cells can reduce both sperm quantity and quality. In some cases, the damage also affects Leydig cells, which are responsible for producing testosterone, further increasing the impact on fertility.
In cases where orchitis causes significant long-term damage and sperm production is impaired, different testicular sperm extraction techniques are available, such as testicular biopsy (TESE) or micro-TESE. These procedures make it possible to locate areas of spermatogenesis even in severely damaged testicles.The retrieved sperm can then be used for in vitro fertilization with ICSI, allowing many men with post-orchitis azoospermia to become biological fathers.