If the haematocele is not drained, a clotted haematocele usually results. The sac may calcify. Clotted hydrocele may result from a slow spontaneous ooze of blood into the tunica vaginalis. It is usually painless and by the time the patient seeks help, it may be difficult to be sure that the swelling is not due to a testicular tumour. Indeed, a tumour may present as a haematocele. Occasionally, severe infection can be introduced by aspiration. Simple aspiration, however, often may be used as a temporary measure in those cases where surgery is contraindicated or must be postponed. Postherniorrhaphy hydrocele is a relatively rare complication of inguinal hernia repair. It is possibly due to interruption to the lymphatics draining the scrotal contents. Infection which may lead to pyocele. Atrophy of testis in long standing cases.Complications are often diagnosed post-operatively, which can be differentiated through duplex ultrasound scanning and are bit observed until 24 to 48 hours for early complications such as drainage, infection, formation of haematocele, rupture, etc., but also for 1 to 6 weeks during follow-up on out-patient basis. Cause
A hydrocele can be produced in four ways:

by excessive production of fluid within the sac, e.g. secondary hydrocele
through defective absorption of fluid
by interference with lymphatic drainage of scrotal structures as in case of elephantiasis
by connection with a hernia of the peritoneal cavity in the congenital variety, which presents as hydrocele of the cord

Primary hydroceles
The swelling is soft and non-tender, large in size on examination, and the testis cannot usually be felt.
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

Infantile hydroceles
It does not occur only in infants but it occurs in adults also, a hydrocele is usually an expression of a patent processus vaginalis (PPV). The tunica and the processus vaginalis are distended to the inguinal ring but there is no connection with the peritoneal cavity. Congenital hydroceles
The processus vaginalis is patent and connects with the general peritoneal cavity. The communication is usually too small to allow herniation of intra-abdominal contents. Digital pressure on the hydrocele does not usually empty it, but the hydrocele fluid may drain into the peritoneal cavity when the child is lying down. Ascites or even ascitic tuberculous peritonitis should be considered if the swellings are bilateral. Encysted hydrocele of the cord
There is a smooth oval swelling near the spermatic cord which is liable to be mistaken for an inguinal hernia. The swelling moves downwards and becomes less mobile if the testis is pulled gently downwards. Rarely, a hydrocele develops in a remnant of the processus vaginalis somewhere along the course of the spermatic cord. This hydrocele also transilluminates, and is known as an encysted hydrocele of the cord. In females, a related region in females, a multicystic hydrocele of the canal of Nuck sometimes presents as a swelling in the groin.