Brief Answer:
Your answers as follows...

Detailed Answer:
I read your question carefully and I understand your concern.

I am assuming since you mention the hips you mean spinal stenosis in the lumbar region (it can happen also in the neck). It means narrowing of the spinal channel where the nerves and spinal cord are situated, usually due to chronic degenerative arthritis of the spine.

Regarding how serious it is, while it is not something life threatening, it can on the other hand cause severe pain and limitations in mobility. So (depending on the degree) it can cause serious disability when severe.

It causes pain in the lower back pain radiating in the buttocks and the legs in the form of shooting pain (sciatica), numbness, tingling. In some severe cases there may be also bladder control issues (it would constitute a medical emergency needing emergency surgery). Often pain may be exacerbated by standing or walking and alleviated by lying down or bending forwards.
However not all patients with spinal stenosis have symptoms, as I said it depends on severity. Many people your age have spinal stenosis as there are degenerative changes of the spine, but only some have symptoms which warrant treatment. So it must correlate with the symptoms, while pain may radiate in the hip region it is not that typical, if pain only in the hips then arthritis of the hip joint is more likely as a cause.

As for what can be done, first step is physical therapy, exercises to increase strength and elasticity of back muscles in order for them to better support the spine and remain active. Pain killers may also be needed to alleviate the pain.
If not enough epidural injections of steroids may achieve symptom control for some time.

In advanced cases surgery where severe symptoms persist despite physical therapy and pain medication, surgery is needed.

I remain at your disposal for other questions.

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