Inguinal hernia overview

# Overview
Inguinal hernia may be classified according to integrity of the posterior wall and the deep inguinal ring into 4 groups. Inguinal hernia may be classified according to presence or absence of a peritoneal sac, size of the internal ring and integrity of the posterior wall of the canal into 5 groups. Directed inguinal hernia is caused by protrusion through Hesselbach's triangle, passes medial to inferior epigastric vessels. Indirected inguinal hernia is caused by passes through internal inguinal ring, traverses inguinal canal to external ring, and may extend into scrotum in males and labia major in females. Common causes of inguinal hernia include combination of increased pressure within the abdomen and a pre-existing weak spot in the abdominal wall, chronic coughing or sneezing, heavy lifting such as weightlifting, abdominal wall defects and advanced age. Inguinal hernia must be differentiated testicular torsion, epididymitis, hydrocele, varicocele, spermatocele, epididymal cyst and testicular tumor. Male are more commonly affected by inguinal hernia than female. The male to female ratio is approximately 9 to 1. Common risk factors in the development of inguinal hernia include history of hernia or prior hernia repair, older age, male gender, obesity. The symptoms of inguinal hernia usually develop in the 4th decade of life. Prognosis is generally good, and mortalilty is very rare. Symptoms of inguinal hernia include nausea and vomiting, heaviness or dull discomfort in the groin, especially when straining, lifting, coughing, or exercising that improves when resting. Patients with inguinal hernia usually appear good. Physical examination of patients with inguinal hernia is usually remarkable for bulge in the groin, painless scrotal mass and palpable abdominal mass may be present. Pharmacologic medical therapies for inguinal hernia include pain reliever, antibiotics, topical medications. Surgery is the mainstay of treatment for inguinal hernia and there are many types of surgical techniques.

# Historical Perspective
Reinforcement of the anterior wall of the inguinal canal and tightening of the external inguinal ring was first discovered by Stromayr in 1559. In 1871, new use of carbolized catgut ligature was developed by Marcy to treat inguinal hernia. Twisted and suture-transfixed the peritoneal sac in the lateral musclesthrough the external ring was developed by Kocher to treat inguinal hernia.

# Classification
Inguinal hernia may be classified according to integrity of the posterior wall and the deep inguinal ring into 4 groups. Inguinal hernia may be classified according to presence or absence of a peritoneal sac, size of the internal ring and integrity of the posterior wall of the canal into 5 groups.

# Pathophysiology
Directed inguinal hernia is caused by protrusion through Hesselbach triangle, passes medial to inferior epigastric vessels. Indirected inguinal hernia is caused by passes through internal inguinal ring, traverses inguinal canal to external ring, and may extend into scrotum in males and labia majora in females.

# Causes
Common causes of inguinal hernia include combination of increased pressure within the abdomen and a pre-existing weak spot in the abdominal wall, chronic coughing or sneezing, heavy lifting such as weightlifting, abdominal wall defects and advanced age.

# Differentiating Inguinal hernia overview from Other Diseases
Inguinal hernia must be differentiated testicular torsion, epididymitis, hydrocele, varicocele, spermatocele, epididymal cyst and testicular tumor.

# Epidemiology and Demographics
The incidence of inguinal hernia is approximately 110 per 100,000 individuals in years aged 16-24 years to 2000 per 100,000 person years aged 75 years or above in men. The prevalence of inguinal hernia is approximately 1700 per 100,000 individuals for all ages and 4000 per 100,000 for those aged over 45 years worldwide. The incidence of inguinal hernia increases with age; the median age at diagnosis is 40-59 years. Male are more commonly affected by inguinal hernia than female. The male to female ratio is approximately 9 to 1.

# Risk Factors
Common risk factors in the development of inguinal hernia include history of hernia or prior hernia repair, older age, male gender, obesity.

# Screening
There is insufficient evidence to recommend routine screening for inguinal hernia.

# Natural History, Complications, and Prognosis

## Natural History
The symptoms of inguinal hernia usually develop in the 4th decade of life, and start with symptoms such as bulging, heaviness, burning, or aching in the groin.

## Complications
Common complications of inguinal hernia include bowel obstruction, bowel strangulation and incarceration.

## Prognosis
Prognosis is generally good, and mortality is very rare.

# Diagnosis

## Diagnostic Criteria
The diagnosis of inguinal hernia is based on clinical examination and symptoms.

## History and Symptoms
Symptoms of inguinal hernia include nausea and vomiting, heaviness or dull discomfort in the groin, especially when straining, lifting, coughing, or exercising that improves when resting.

## Physical Examination
Patients with inguinal hernia usually appear good. Physical examination of patients with inguinal hernia is usually remarkable for bulge in the groin, painless scrotal mass and palpable abdominal mass may be present.

## Laboratory Findings
Laboratory findings is usually normal among patients with inguinal hernia.

## Imaging findings
CT scan may be helpful in the diagnosis of inguinal hernia. Findings on CT scan suggestive of inguinal hernia include defect in the abdominal wall muscles, appearance of bowel loops within the lesion, lateral crescent sign.

## Other Diagnostic Studies
There are no other diagnostic studies associated with inguinal hernia.

# Treatment

## Medical Therapy
Pharmacologic medical therapies for inguinal hernia include pain reliever, antibiotics, topical medications.

## Surgery
Surgery is the mainstay of treatment for inguinal hernia and there are many types of surgical techniques.

## Prevention
Effective measures for the primary prevention of inguinal hernia include avoid becoming overweight, avoid rapid weight loss, use good body mechanics meanwhile lifting heavy objects.