Chronic pain is a complex condition that varies widely among individuals. It depends on many factors, including the nature of the injury, the affected body part, and how the brain and spinal cord interpret signals from the body. While often caused by an initial injury, chronic pain can persist long after healing, due to nerve damage that makes the pain more intense and long-lasting. In some cases, chronic pain can arise without any prior injury, often due to an underlying health condition.
Types of Chronic Pain
Nociceptive pain vs. neuropathic pain
To better understand and treat chronic pain, medical professionals typically categorize it into two main types, based on the location of the damage and how the body processes pain signals. These two types are nociceptive pain and neuropathic pain.
Nociceptive pain
Nociceptive pain is the most common form of chronic pain and is caused by damage to body tissues. This type of pain is typically linked to injuries to muscles, joints, bones, tendons, or skin. When these tissues are injured, nociceptors (pain receptors) are activated and send pain signals to the brain. In cases of chronic nociceptive pain, these signals continue long after the injury has healed, creating ongoing pain.
Nociceptive pain can result from various external injuries. Some common causes include:
- Rotator cuff injuries
- Tennis or golfer’s elbow
- Ankle sprains
- Plantar fasciitis
- Osteoarthritis
- Bursitis
Nociceptive pain can be divided into two main categories: somatic pain and visceral pain.
Somatic pain
Somatic pain is caused by injury to the outer body, including the skin, muscles, tendons, joints, and bones. This type of pain is typically localized and can feel like aching, throbbing, or sharp pain. Chronic conditions like arthritis or joint injuries often result in somatic pain.
Symptoms of somatic pain:
- Aching
- Throbbing
- Sharp or stabbing pain
Visceral pain
Visceral pain is caused by injury or dysfunction of the internal organs, such as the bladder, intestines, or heart. It can also result in referred pain, where the pain is felt in a part of the body other than the source of the injury. Chronic visceral pain can occur with conditions like endometriosis, bladder pain, or migraines.
Symptoms of visceral pain:
- Deep, dull aching
- Cramping
- Referred pain in other areas of the body
Neuropathic pain
Neuropathic pain, also known as nerve pain, occurs when the nervous system — either the brain, spinal cord, or peripheral nerves — is damaged. This type of pain results from changes in how sensory information is processed, leading to abnormal pain signals being sent to the brain. Conditions that affect the nervous system, such as diabetes, stroke, or multiple sclerosis, are common causes of neuropathic pain.
Neuropathic pain often arises from conditions that directly affect the nervous system. Some common causes include:
- Diabetes
- Stroke
- Guillain-Barré syndrome
- Multiple sclerosis
- Complex regional pain syndrome
Additionally, neuropathic pain can also be caused by:
- Phantom limb pain (following limb amputation)
- Spinal nerve compression (e.g., carpal tunnel syndrome, sciatica)
- Nerve damage from trauma, such as spinal cord injury
Neuropathic pain is often described as one of the most intense and persistent types of chronic pain. It primarily affects areas like the lower back, neck, and limbs, and its symptoms include:
- Shooting pain
- Burning or stinging sensations
- Stabbing pain
- Tingling, or a sensation of “pins and needles”
- Numbness or loss of sensation
Because neuropathic pain involves the disruption of nerve pathways, it may not always correspond directly to an injury site and can cause abnormal sensations even in areas where no injury occurred.
