I'm guessing I have arthritis in my hip, (my mother does, my grandmother did), but why does it mainly hurt when I lay down? It doesn't bother me a whole lot during the day, but is very painul as soon as a lay down.
Most of the time when people are talking about "hip" pain, they are really referring to pain over the "greater trochanter". The greater trochanter is the big bone on the side of the pelvis and represents the top of the femur, the femoral head. Many muscles attach on the greater trochanter, primarily the large butt muscles. These muscles can develop tendonitis and even bursitis. Tendonitis and bursitis at the greater trochanter causes pain, particularily when lying on that side.
If one had actual hip joint arthritis, that pain is located primarily in the groin. The groin is the actual location of the hip joint. Hip joint pain can also be more painful when laying down (side-lying) especially in women because of the shape of our pelvis.
Putting a thick pillow between the knees can help with both hip and "hip"/trochanter pain when lying on your side. This video provides exercises that can help relieve your hip pain. It's important to treat this hip pain and stay active to avoid surgery, and so it doesn't progressively get worse.
Ultimately, you should let your doctor exam you in order to determine which "hip" hurts, and therefore which area to treat and concentrate on.
Thank you for your comments. I've had pain in my back and left hip now for months. It stared out with pain and spasms in my lower back off/on when standing or walking. Lying down was fine. But then I started having pain in the outside of my left leg when lying on that side. The medical neurosurgeon gave me injections for hip bursitis and ordered injections in my lower facet joints in my back. The facet injections did nothing, but after the hip injections I could then sleep on both sides which was a relief. But now I'm noticing another issue. When I'm in bed, if I lay on either side I'm fine. It's when I try to roll to the other side not only do I have some back pain (which I can handle, especially if I apply pressure to my lower back with my fist while I turn) but it's like half-way through my turn, when I'm on my back, I get this terrible pain I think in my hip joint. Lifting my left leg slightly, or laying it flat, only makes things worse. Someone on another site said that their hip slips out of joint, and ??? Makes me wonder if that's what's happening? The pain is terrible. I don't know if it's gotten worse since the bursitis injections or if I now just notice it more. Last fall when all this started I thought it was all back pain that radiated into my hip, butt and upper leg. But now I'm wondering if I really have 3 issues: bursitis (resolved?), lower back pain, and something with the actual hip joint. I'm seeing the medical neurosurgeon again soon but struggling with how to describe all of this...he's kind of hard to talk to. :-(
I started having pain in my hips while sleeping on my side during my first pregnancy. I figured it was due to the changes in my hips/pelvis due to the pregnancy. However, I have continued to have the pain while sleeping 4 years and 2 pregancies later. I figured it was not my mattress because i still had the pain when sleeping elsewhere. I am also a runner, so I am assuming that I have some kind of tendonitis or bursitis, in both hips. What do you suggest for relief?
the answer is back pain