Pain extending from the hip down to the knee can be a source of significant discomfort, often interfering with daily activities. While the sensation may feel localized to the hip or knee, its true source can sometimes be found elsewhere along the nerve pathways, muscles, or joints connecting these areas.
Nerve Compression Issues
Sciatica results from irritation or compression of the sciatic nerve, which originates in the lower back and extends down the back of each leg. Symptoms typically include sharp, shooting, or burning pain that radiates along the nerve’s path, often with numbness, tingling, or muscle weakness in the affected leg.
Common causes of sciatic nerve compression include a herniated disc in the lumbar spine, where the inner material of an intervertebral disc pushes out and presses on the nerve root. Spinal stenosis, a narrowing of the spinal canal, can also compress the sciatic nerve as it exits the spinal column. Piriformis syndrome presents another scenario where the sciatic nerve can become compressed. In this condition, the piriformis muscle, located deep in the buttock, spasms or tightens, irritating the underlying sciatic nerve. This can mimic sciatica symptoms, causing pain that travels from the buttock down the back of the thigh and sometimes into the calf.
Muscle and Tendon Problems
Issues within the muscles and tendons of the hip and thigh are a common source of pain that can radiate towards the knee. Hamstring strains or tears, involving the group of three muscles along the back of the thigh, can cause pain extending from the buttock down to the knee. These injuries often occur during activities requiring sudden acceleration, stretching, or forceful contraction. The pain is typically felt deep in the posterior thigh and can be exacerbated by movement or stretching.
Iliotibial (IT) band syndrome occurs when the thick band of fibrous tissue running along the outside of the thigh, from the hip to just below the knee, becomes inflamed or tight. This inflammation commonly results from repetitive motion, such as running or cycling, causing the IT band to rub against the bony prominence of the hip or knee. The pain is typically felt on the outer aspect of the hip and can radiate down the side of the thigh to the outside of the knee. Other muscle strains or tendinitis in the hip or thigh, such as those affecting the quadriceps or hip adductors, can also refer pain downwards. These conditions often arise from overuse, unaccustomed physical activity, or direct trauma, leading to localized pain that can spread along the muscle or tendon’s length.
Joint and Soft Tissue Conditions
Conditions affecting the hip or knee joints, or surrounding soft tissues like bursae, can manifest as pain radiating from the hip to the knee. Hip osteoarthritis, a degenerative joint disease, involves the breakdown of cartilage within the hip joint. This leads to deep, aching pain often felt in the groin, but can frequently radiate down the front or side of the thigh towards the knee. The pain typically worsens with activity and improves with rest, and can be accompanied by stiffness and reduced range of motion.
Knee osteoarthritis involves cartilage degradation within the knee joint, primarily causing pain around the knee itself. In some cases, pain from the knee can be referred higher up into the thigh, contributing to hip-to-knee discomfort. Bursitis, the inflammation of a bursa (a small fluid-filled sac that cushions bones, tendons, and muscles near joints), can also cause radiating pain. Trochanteric bursitis, affecting the bursa on the outer side of the hip, leads to pain over the hip’s bony prominence that can extend down the outside of the thigh. Prepatellar or infrapatellar bursitis, located at the front of the knee, can cause localized knee pain that might feel like it’s radiating upwards due to swelling and tenderness.
When to Consult a Doctor
Consult a doctor if you experience pain radiating from your hip down to your knee, especially if certain symptoms are present. Seek prompt medical attention if the pain is severe, comes on suddenly after an injury, or is accompanied by weakness in the leg. Loss of bowel or bladder control alongside leg pain is a serious symptom requiring immediate medical attention.
It is also advisable to see a healthcare provider if the pain progressively worsens, does not improve with rest, or significantly interferes with daily activities. Persistent numbness or tingling, or any signs of infection such as redness, warmth, or fever in the affected area, warrant medical evaluation.