My Husband Has Spinal Stenosis And A Couple Of Herniated

my husband has spinal stenosis and a couple of herniated discs in his lower back. For the past couple of days he has been experiencing pain in his left hip. He could not sleep on that side last night and today he woke up and had difficulty walking, a lot of pain. A few minutes ago I had him lay down on his right side so I could look at his hip. It is visably swollen on the outer hip bone and highly painful to touch. There is no visible skin aberation. Just the swelling and pain. He does not recall doing anything that would have caused an injury.