When your hips and knees hurt at the same time, it usually means one of three things: a shared condition like osteoarthritis is affecting both joints, a problem in one joint is creating strain on the other, or a hip issue is sending pain signals down to your knee. The overlap isn’t a coincidence. These two joints are deeply connected through shared muscles, connective tissue, and nerve pathways, so problems in one almost always show up in the other eventually.
Osteoarthritis Is the Most Common Cause
Osteoarthritis, the wear-and-tear form of arthritis, affects roughly 365 million knees worldwide, with the hip close behind as the second most commonly affected joint. It happens when the cartilage cushioning the ends of your bones gradually breaks down, leaving bone surfaces exposed to friction. Because both your hips and knees are large, weight-bearing joints that absorb impact every time you walk, stand, or climb stairs, they tend to wear down along similar timelines.
The major risk factors are age, carrying extra weight, being female, previous joint injuries, and physical inactivity. What’s notable is that hip and knee pain shows up in more than 20% of adults even in the 29 to 39 age range, well before most people develop visible cartilage damage on imaging. Joint injuries and excess weight during early adulthood put you on a trajectory toward symptomatic osteoarthritis later, which means the pain you’re feeling now could be an early signal even if an X-ray looks relatively normal.
Osteoarthritis pain typically feels stiff and achy, worst after periods of inactivity or at the end of a long day. You might notice it takes a few minutes to “warm up” after sitting, and that the stiffness eases once you start moving. It tends to come on gradually over months or years rather than appearing overnight.
How a Hip Problem Can Create Knee Pain
Your hip and knee don’t operate independently. They’re part of a kinetic chain, meaning the position and function of one joint directly affects the other. When the muscles around your hip are weak, particularly the gluteal muscles on the side and back of your pelvis, your body compensates in ways that punish your knee.
Here’s the specific mechanism: during walking, your gluteal muscles keep your pelvis level when you’re standing on one leg (which happens with every single step). If those muscles are weak, your pelvis drops momentarily on the opposite side. That drop causes your knee to dive inward toward your other leg, compressing the kneecap against the joint surface beneath it. Repeat this thousands of times a day, and you develop chronic knee pain that actually originates from hip weakness.
This pattern is especially common in people who sit for long hours, runners who haven’t built hip strength, and anyone recovering from a hip injury. The knee pain often shows up on the front of the knee or around the kneecap, and it worsens with stairs, squatting, or prolonged sitting.
Your Hip Can Send Pain Directly to Your Knee
Sometimes what feels like knee pain is actually referred pain from the hip. This is a well-documented phenomenon caused by the nerve anatomy of the pelvis and leg. The knee joint shares nerve branches with the hip, including branches of the femoral, sciatic, obturator, and saphenous nerves. When a hip joint is inflamed or damaged, pain signals can travel along these shared nerve pathways and register as knee pain, even though nothing is wrong with the knee itself.
This is one reason doctors will examine your hip when you come in complaining about knee pain. If your knee looks fine on examination but the pain persists, the source may be upstream at the hip. Referred pain from the hip typically shows up on the front or inner side of the knee and doesn’t reproduce with direct pressure on the knee itself.
IT Band Syndrome Bridges Both Joints
The iliotibial band is a thick strip of connective tissue running from your hip bones all the way down the outside of your thigh to the top of your shinbone. When it becomes irritated, it causes an aching or burning pain on the outside of the knee that can spread upward into the hip.
This condition is common in runners and people who do repetitive bending and straightening of the knee. You might notice the pain only during exercise at first, but as it progresses, it can start earlier in your workout and linger afterward. Going up and down stairs often makes it worse. Because the band spans from hip to knee, tightness or irritation anywhere along its length can produce symptoms at both ends.
Inflammatory Arthritis Feels Different
If your joint pain came on relatively quickly, affects both sides of your body symmetrically, and comes with noticeable morning stiffness lasting 30 minutes or longer, the cause may be inflammatory rather than mechanical. Rheumatoid arthritis is an autoimmune condition where your immune system attacks the lining of your joints, causing swelling, pain, and eventually joint damage.
Rheumatoid arthritis typically starts in smaller joints like the hands and feet, then progresses to larger joints including the hips and knees if untreated. The key differences from osteoarthritis: the stiffness is worst in the morning rather than at the end of the day, the joints may feel swollen or “boggy” to the touch, and the pattern tends to be symmetric (both knees, both hips). Blood tests can detect markers that help confirm the diagnosis, and early treatment makes a significant difference in preventing joint erosion.
Body Weight and Joint Load
The relationship between body weight and joint pain is more dramatic than most people realize. Research has shown that each pound of body weight translates to roughly four pounds of force on your knees with every step. Lose 10 pounds and you remove about 40 pounds of compressive force from your knees during daily walking. Over the course of a day, that adds up to tens of thousands of pounds of reduced stress.
This multiplier effect explains why even modest weight loss can produce noticeable pain relief in people with hip and knee pain. It also explains why weight gain, even a relatively small amount, can tip previously comfortable joints into painful territory. The hips experience a similar amplification, though the ratio is slightly different due to the joint’s ball-and-socket design.
What Doctors Look For During an Exam
When you see a provider for combined hip and knee pain, they’ll use specific physical tests to figure out which joint is the true source of your symptoms. One common test involves lying on your back while your leg is placed in a figure-four position, with your ankle resting on your opposite knee. This maneuver, called the FABER test, stresses the hip joint, the sacroiliac joint in your pelvis, and the hip flexor tendon all at once. Where you feel pain during this test tells your provider which structure is involved: groin pain points to the hip flexor or hip joint, pain on the side suggests irritation near the outer hip, and pain in the back of the pelvis implicates the sacroiliac joint.
Another test checks whether your hip muscles are strong enough to keep your pelvis level. You’ll be asked to stand on one leg. If your pelvis drops more than about 2 centimeters on the opposite side, it indicates your gluteal muscles aren’t doing their job, which may be driving your knee symptoms. Imaging with X-rays or MRI usually comes after the physical exam and targets whichever joint the hands-on tests identify as the likely culprit.
Signs That Need Prompt Attention
Most hip and knee pain develops gradually and responds to activity modification, strengthening, and weight management. But certain patterns warrant faster evaluation. A joint that becomes rapidly swollen, warm, and painful over hours to days could indicate infection or a gout flare, both of which need treatment quickly. Inability to bear weight at all, significant swelling after a fall or injury, or pain accompanied by fever are reasons to seek same-day care. Pain, warmth, and swelling in one calf, especially if it’s worse than the joint symptoms, could signal a blood clot and needs immediate evaluation.
For the more common scenario of gradual, persistent aching in both your hips and knees, the most productive first steps are building hip and gluteal strength through targeted exercises, addressing any excess weight, and staying physically active without overloading the joints. Swimming, cycling, and walking on flat surfaces tend to be well tolerated. Strengthening the muscles that support these joints reduces the load on the cartilage itself and often produces meaningful pain relief within a few weeks.