An inguinal hernia occurs when a segment of internal tissue, such as a piece of fat or a loop of intestine, protrudes through a weak area in the abdominal wall, typically near the groin. This protrusion creates a visible or palpable bulge. While hernias often cause discomfort when standing or straining, experiencing pain when lying down is a specific symptom that suggests unique mechanical factors are at play.
Understanding Inguinal Hernias
An inguinal hernia forms in the inguinal canal, a natural passage in the lower abdominal wall through which structures like the spermatic cord in men and the round ligament in women pass. The abdominal wall is normally a strong barrier, but acquired weakening or genetic predisposition allows abdominal contents to push through this opening. This creates a hernial sac holding the protruding tissue.
The two main types are indirect, which is often congenital due to a failure of a passageway to close after birth, and direct, which develops over time from weakening of the abdominal muscles in adults.
Factors that increase pressure inside the abdomen contribute to forming or enlarging a hernia, including chronic coughing, straining during bowel movements, or repeated heavy lifting. Being male significantly increases the risk, with men being up to ten times more likely to develop an inguinal hernia than women.
The Mechanism of Pain When Supine
For many people, the bulge and associated discomfort of an inguinal hernia lessen or disappear completely when they lie down. This gravity-assisted position allows the protruding tissue to fall back into the abdominal cavity, relieving tension on surrounding tissues and nerves. If pain occurs or increases when you are supine, however, it suggests that this repositioning is not happening smoothly or is causing a new type of compression.
When you transition from standing to lying flat, the distribution of intra-abdominal fluid and pressure shifts. This change can sometimes force a larger volume of tissue into the already tight neck of the hernial sac, even without the downward pull of gravity. The sudden increase in volume within the confined space can result in a sharp, temporary increase in pain as the tissue is compressed.
The pain may also result from compression against nearby nerves. The inguinal canal houses several sensory nerves. If the shifting contents press against these nerves as the tissue settles in the supine position, it can cause a distinct, sharp, or burning pain. This nerve irritation is noticeable when the supporting abdominal muscles relax while lying down, allowing the hernia to rest directly on sensitive structures.
In some cases, the pain when lying down can signal that the hernia is not fully reducible, meaning the contents do not completely slide back into the abdomen. If the tissue is partially stuck, the positional change may cause it to pivot or become slightly kinked at the opening. This mechanical tension against the surrounding abdominal fascia and muscles registers as pain, indicating a more complex mechanical issue.
Recognizing Signs Requiring Urgent Care
While a change in discomfort is often mechanical, persistent or severe pain warrants immediate medical evaluation, as it could indicate a serious complication. The primary concern is incarceration, where the protruding tissue becomes trapped and cannot be manually pushed back into the abdomen. This trapped tissue is subject to increased pressure, causing swelling and tenderness.
An incarcerated hernia can quickly progress to a strangulated hernia, which is a life-threatening medical emergency. Strangulation occurs when the blood supply to the trapped section of tissue, often a part of the intestine, is cut off. The lack of blood flow causes the tissue to die, leading to potential infection and bowel perforation.
Specific red flag symptoms demand immediate attention: a sudden, rapid increase in pain that does not subside, especially if the pain is severe and continuous. Other signs include nausea, vomiting, or an inability to pass gas or have a bowel movement, which suggest a bowel obstruction. If the skin over the hernia bulge becomes discolored, turning red, purple, or dark, or if you develop a fever or a rapid heart rate, you must seek emergency care right away.
Options for Managing the Condition
Management of an inguinal hernia depends on the severity of symptoms and the patient’s overall health. For men with small hernias causing minimal symptoms, watchful waiting may be an acceptable approach. This involves monitoring the hernia closely and delaying surgery until symptoms become bothersome or the hernia enlarges.
However, studies show that a significant number of patients initially placed on watchful waiting eventually opt for surgery, primarily because of increasing pain. For symptomatic hernias, or those that are difficult to reduce, surgical repair, known as hernioplasty, is the definitive treatment. Surgery prevents the risk of future incarceration or strangulation and resolves the discomfort.
Surgical Techniques
The two main surgical techniques are open repair and laparoscopic (minimally invasive) repair. Open repair involves a single, larger incision at the groin, and recovery time is often slightly longer.
Laparoscopic repair uses several small incisions and specialized instruments, resulting in less post-operative pain and a quicker return to normal activities. Laparoscopic surgery may be preferred for patients with hernias on both sides or those with recurrent hernias. Open repair may be necessary for patients with extensive prior abdominal scarring.