SYMPTOMS

What is referred pain?

When certain internal organs, such as the viscera or intestines, develop lesions, the affected area may not produce distinct sensations, or it may be difficult to pinpoint the source of the pain. However, specific undamaged areas on the body's surface may experience pain or hypersensitivity (e.g., sunlight becoming glaring, common sounds becoming harsh, etc.). This phenomenon is referred to as referred pain.

What are the characteristics of referred pain?

• The pain is usually not severe.
• The pain is typically deep.
• Pressing the muscles or skin in the painful area generally does not cause significant discomfort.
• The pain may come and go intermittently.

What symptoms often accompany referred pain?

• Nausea or vomiting.
• Nervousness or anxiety.
• Increased sweating, etc.

Which organs are associated with referred pain?

Primarily the intestines and visceral organs, such as the lungs, heart, liver, kidneys, appendix, etc.

What does the occurrence of referred pain indicate?

Referred pain often serves as a warning sign of potential internal organ disorders.

Compared to the body's surface, internal organs have far fewer sensory nerves and are less sensitive to pain.

Thus, when these organs experience issues, the sensations may be vague, and the pain location unclear. However, corresponding areas on the body's surface may exhibit noticeable pain.

How does referred pain occur?

The exact cause of referred pain remains unclear.

A common theoretical hypothesis suggests:

The pain-sensing nerves from internal organs and those from corresponding body surfaces converge at the same level in the spinal cord before transmitting signals to the brain.

When visceral pain signals are sent to the brain, they merge with signals from the body's surface, making it difficult for the brain to distinguish the pain's origin.

Since the body's surface is more frequently exposed to external stimuli, most pain we perceive comes from the skin. As a result, the brain may mistakenly attribute visceral pain to the skin, leading to what we call "referred pain."

TREATMENT

How to treat referred pain?

Referred pain is merely a symptom. Identifying the underlying cause is the key to resolving the issue.

Can I take medication or apply heat/ice for referred pain?

It depends on the situation.

1. Unknown cause

   If the specific cause of referred pain is unclear, blindly applying heat/ice or taking painkillers may temporarily relieve symptoms but could mask the true condition and delay diagnosis and treatment.

   Therefore, if symptoms recur or the pain becomes unbearable, seek medical examination—especially for patients with pre-existing conditions.

2. Known cause

   If the cause is confirmed, use medication under a doctor's guidance.

   • Mild pain: Non-narcotic analgesics (e.g., ibuprofen, acetaminophen) may suffice.
   • Severe pain: Synthetic analgesics (e.g., pethidine) can be used.
   • Severe referred pain from cancer or other diseases: Weakly addictive narcotics (e.g., morphine) may be prescribed as needed.

   During episodes, stay relaxed. Listening to music, practicing deep breathing, or focusing on inhalation/exhalation can help distract from the pain.

DIAGNOSIS

Referred pain frequently occurs in the abdomen. Which departments should I visit?

General surgery or gastroenterology.

What tests are needed when referred pain occurs?

• Physical examination, where the doctor uses hands for inspection to aid diagnosis; simple and practical, commonly used in clinical practice. For example, in cholecystitis, the doctor will firmly press the patient's gallbladder point. If the patient feels pain upon deep inhalation and suddenly holds their breath, this is called a "positive Murphy's sign," indicating gallbladder disease.
• Ultrasound. Ultrasound helps locate the lesion and assists doctors in diagnosing the primary condition.
• Blood test. The levels of white blood cells and lymphocyte counts in blood tests can help determine whether there is an infection.

POTENTIAL DISEASES

Is referred pain always a sign of appendicitis?

Not necessarily.

In the early stages of appendicitis, pain often occurs around the navel or in the upper right abdomen and becomes more noticeable when lying down or standing. As the condition progresses, the pain typically shifts to the lower right abdomen, a phenomenon medically referred to as "migratory right lower abdominal pain."

While appendicitis is indeed a classic and common cause of referred pain, experiencing referred pain does not always indicate appendicitis.

What other conditions might referred pain indicate?

• Myocardial ischemia or infarction. Before an acute heart attack, the heart itself may not exhibit obvious discomfort. Instead, pain may manifest in the precordial area, left shoulder, inner left arm, or left side of the neck. Some patients may even experience "toothache."

  These seemingly unrelated pains are actually distress signals from the heart. Early recognition can aid in timely intervention.

  However, pain in the left shoulder or neck should also be differentiated from primary conditions like frozen shoulder or lymphadenitis.

• Cholecystitis. With gallbladder inflammation, pain may not be prominent at the site of the organ but rather in the right shoulder. If there’s no recent injury to the right shoulder or nearby muscles, cholecystitis should be considered.

• Pancreatitis, gastric, or duodenal ulcers. These digestive system-related inflammations often cause referred pain in the back.

• Kidney stones. These typically cause pain in the groin (the area where the thigh meets the torso) or tenderness when tapping the lower back.