Pain on the right side of the abdomen can be either in the upper part (RUQ ~ right upper quadrant) or lower part (RLQ ~ right lower quadrant). Abdominal pain is a non-specific symptom that can be attributed to a host of conditions. Therefore the presence of other signs and symptoms in association with the pain is important to consider in the differential diagnosis. Modalities may include pain that commences, worsens or eases with change in position, eating, hunger, changes in bowel movements and movement.
The final diagnosis should be done my a medical professional after a thorough case taking and additional diagnostic investigations like an abdominal ultrasound, x-ray, CT scan or MRI. Blood tests and specialized investigative techniques like an endoscopy, colonoscopy or barium enema may also be needed. Broadly, right sided abdominal pain can be attributed to the right lung, diaphragm, kidney, liver, gallbladder, head of the pancreas, small intestine, cecum, ascending colon or transverse colon of the large intestine and peritoneum. The pelvic organs and structures should also be considered in lower right sided abdominal pain. Pain in the abdomen may not originate from this area and can be referred or radiate from the chest, pelvis and back.
UPPER Right Abdominal Pain
Pain in the upper right abdominal region may be superficial or deep. Superficial causes may be attributed to the abdominal wall (skin and muscles), peritoneum, liver and gallbladder. Deeper pain may be due to the liver, bile ducts, stomach, duodenum and kidneys.
Pain may be associated with the lung tissue itself (rare), lining of the lung (pleura) or space around the lung (pleural space). Lung and pleural diseases that may causes right sided abdominal pain include :
- Pneumonia (bacterial or viral) of the lower lobe of the right lung.
- Pleurisy or pleuritis (inflammation of the lung membrane) from infection, trauma and so on.
Signs and symptoms may include difficulty breathing, coughing, and pain upon breathing/moving.
The liver is an important consideration in upper right abdominal pain as it occupies most of this region. As a large organ with diverse functions, and the central processing unit of nutrients, the liver is prone to a variety of disorders. Liver conditions that may cause right sided abdominal pain include :
- Enlarged liver due to heart failure, hepatitis, fatty liver, lymphoma, leukemia, etc.
- Liver cancer or metastases of other cancer into the liver.
Signs and symptoms may include changes in bowel movements and consistency of stool, nutrient deficiencies, jaundice, changes in appetite and weight loss.
GALLBLADDER/ BILIARY TRACT
The gallbladder stores bile that is produced in the liver. This fluid contains various compounds, particularly waste substances and fats, and can emulsify fats in the gut to allow for digestion and subsequent absorption. Bile is passed through the biliary tracts which communicates with the pancreatic duct before emptying into the duodenum, the first part of the small intestine. Conditions of the gallbladder and biliary tree that may causes right sided abdominal pain includes :
- Gallstones or bile duct stones
- Gallbladder inflammation (cystitis), mostly due to gallstones.
- Inflammation or blockage of the biliary tree (cholangitis) (cystic, or common bile duct).
- Gallbladder and biliary cancer are rare.
Signs and symptoms may include jaundice, fatty stools and episodes of pain that are intense (colicky) and generally arise after eating.
The duodenum is the first part of the small intestine and an important site for digestion. It receives the partially digested food mixed with gastric acid and enzymes from the stomach and then bile and digestive enzymes from the pancreas. It is often affected with the same pathologies that afflict the stomach, often a combination of infection and the presence of gastric acid in the duodenum for prolonged periods. Some of the conditions of the duodenum that may cause right sided abdominal pain include :
- Duodenal ulcer
- Duodenitis – inflammation of the duodenum similar to gastritis (stomach).
Signs and symptoms include severe pain after eating, although the pain may sometimes ease slightly with food, change in bowel movements, excessive belching and bloating.
The abdominal muscles comprise several groups of muscles that protect the abdominal contents, stabilize the trunk during movement and help with changes in position. Since the abdominal cavity lacks an extensive skeletal protection like the thoracic cavity, the abdominal muscles have to contend with significant impact in trauma. Some conditions affecting the abdominal muscles that may cause right sided abdominal pain includes :
- Strained muscles – common cause.
- Blunt force trauma
- Rectus sheath haematoma
- Psoas abscess
Signs and symptoms generally include pain when moving and tenderness on palpation of the affected area.
The kidney is responsible for filtering the blood and forming urine. Electrolytes and water are reabsorbed as necessary and the urine is directed down the ureter to the bladder. The kidney is tucked behind and slightly below the liver on the right side of the abdomen to lie shielded by the back part of the ribcage. Some conditions affecting the kidney and ureter that may cause right side abdominal pain includes :
- Pyelonephritis (infection of the right kidney).
- Kidney/urinary stones
- Renal carcinoma
Signs and symptoms include changes in the urine color and composition, alterations in urinary habits and additional signs like blood in the urine (hematuria).
The diaphragm is the large concave muscle that separates the thoracic and abdominal cavities. It is the major muscle of respiration and on the right side, it houses the liver immediately beneath it. When contracted, the diaphragm pushes down the abdominal contents to expand the chest cavity. Some of the conditions of the diaphragm that may cause right sided abdominal pain include :
- Abscess under diaphragm
LOWER Right Abdominal Pain
Lower right abdominal pain may be due to some of the same causes discussed under upper right abdominal pain. With the lower abdominal regions, the continuation with the pelvic cavity means that pathologies of the pelvic organs or structures may also be a cause of pain.
The appendix are a small outpouching from the cecum of the large intestine. It is believed to be a reservoir for the normal intestinal flora (good bowel bacteria). It can become inflamed, obstructed and or infected. This may be related to the surrounding parts of the intestine or other abdominal structures or occur independently. Some of the conditions of lower right sided abdominal pain include :
- Appendicitis (inflammation of appendix)
The small intestine comprises the duodenum, jejunum and ileum. It is the major site of digestion and absorption. Waste products and undigested material pass into the large intestine. The small intestine is also the longest part of the gastrointestinal tract and prone to various conditions that may be a continuation of pathology in the stomach or large intestine. Conditions affecting the small intestine that may cause right sided abdominal pain include :
- Crohn’s disease affecting the last part of the small intestine, called terminal ileum.
The colon is the main part of the large intestine and has been discussed above. The most prominent part lying on the lower right side includes the cecum and ascending colon.
- Volvulus twisting of the cecum (starting part of large intestine), rare.
FEMALE REPRODUCTIVE ORGANS
Gynecological causes of right sided abdominal pain are an important and common cause. It should always be taken into consideration especially if the pain appears to be associated with ovulation or menstrual cycle or there are any menstrual changes that accompany the onset of the pain. A slight discomfort with ovulation and menstruation and mild, short lived pain during pregnancy is normal.
- Ovulation (mid-cycle pain, Mittleschmerz)
- Twisted or ruptured ovarian cyst
- Ectopic pregnancy
- Polycystic ovarian syndrome – PCOS; usually affecting both right and left ovary
MALE REPRODUCTIVE ORGANS
Disorders of the male reproductive are unlikely to cause lower right sided abdominal pain with pain in the pelvis or genitalia. Some conditions to consider include :
- Spermatic cord disorders
- Testes disorders
ABDOMINAL BLOOD VESSELS
The blood vessels in the abdomen include the large aorta and inferior vena cava, with the various branches and tributaries. These blood vessels are prone to a host of diseases that may be isolated to the cardiovascular system or part of a systemic condition. Some of these conditions include :
- Hereditary angioedema
- Atherosclerosis of arteries that supply the intestine
- Sickle Cell Disease
Conditions affecting the skin may be responsible for upper and lower right sided abdominal pain. Skin lesions or deformities may be present, including a rash, swelling and/or redness. Most skin diseases present with itchiness but pain may be seen in the following conditions.
- Herpes zoster
- Dermatitis (eczema) when the skin is broken or there is an infection.
ABDOMINAL MEMBRANE (PERITONEUM)
The peritoneum mainly envelopes the gastrointestinal tract in the abdomen and peritoneal fluid keeps the organs lubricated when making contact with each other. Inflammation, infection and swelling may be associated with peritonitis.