Pain Type Guides

Understand Your Pain

Each condition guide covers symptoms, causes, the latest research, and evidence-based relief strategies tailored to your specific pain type.

Updated 2026-04-07

Back Pain

Back pain is one of the most common medical conditions worldwide, affecting approximately 80% of adults at some point in their lives. Musculoskeletal conditions like back pain affect roughly 128 million adults in the U.S. alone, contributing to over $600 billion in annual socioeconomic costs due to healthcare utilization, early retirement, and lost productivity. The pain ranges from dull, constant aching (nociceptive pain from tissue strain) to sharp, shooting sensations that can indicate nerve involvement (neuropathic pain from disc herniation or spinal stenosis).

50%Updated 2026-04-07

Neck Pain

Neck pain is a widespread condition that affects nearly 30% of adults each year. It occurs when the cervical spine — the seven vertebrae that make up the neck — becomes strained, inflamed, or injured, causing discomfort that can range from mild stiffness to debilitating pain.

25%Updated 2026-04-07

Knee Pain

Knee pain is an extremely common complaint that affects people of all ages. It may result from an injury, such as a ruptured ligament or torn cartilage, or from medical conditions including arthritis, gout, and infections. Roughly 25% of adults experience frequent knee pain.

26%Updated 2026-04-07

Shoulder Pain

Shoulder pain refers to any discomfort in or around the shoulder joint, the most mobile joint in the body. Because of its wide range of motion, the shoulder is particularly susceptible to injury and chronic conditions that affect roughly 18–26% of adults.

50%Updated 2026-04-07

Headaches & Migraines

Headaches are among the most common nervous system disorders, with nearly half of the adult population experiencing at least one headache per year. Migraines, a severe form, affect over 1 billion people worldwide — making them the third most prevalent illness globally. Modern neuroscience classifies migraine pain as involving both peripheral (trigeminal nerve activation) and central sensitization mechanisms. FDG-PET neuroimaging studies reveal that chronic migraine sufferers exhibit hypometabolism in the fronto-temporal brain regions, which may explain why pain persists even without a clear trigger.

Updated 2026-04-07

Arthritis

Arthritis is a broad term for conditions that cause inflammation and pain in the joints. With over 100 different types, the most common are osteoarthritis (OA, caused by cartilage breakdown) and rheumatoid arthritis (RA, an autoimmune attack on the joint lining). It affects over 350 million people worldwide and is a leading cause of disability. OA pain is primarily nociceptive — driven by activation of peripheral TRP nociceptors from mechanical stress — while RA involves chronic inflammatory mediator release, creating an 'inflammatory soup' that lowers pain thresholds and causes both allodynia (pain from normally painless touch) and hyperalgesia (amplified pain response).

40%Updated 2026-04-07

Sciatica

Sciatica refers to pain that radiates along the path of the sciatic nerve — the longest nerve in the body — which runs from the lower back through the hips and buttocks and down each leg. It typically affects only one side of the body and is experienced by up to 40% of people at some point. Sciatica is classified as neuropathic pain — it arises from a direct lesion (usually a herniated disc) compressing the nerve root, causing ectopic nerve firing and loss of normal sensory processing. This explains the characteristic burning, electrical shock-like sensations that differentiate it from simple muscle-based back pain.