Depends. Clinically, the diagnosis is often made by symptoms of neurogenic claudication, in the absence of any overt vascular disease. Typically this a tight or heavy ache in the legs with prolonged standing or walking that resolves quickly with sitting. The diagnosis can be confirmed by mri. Not all patients with MRI evidence of spinal stenosis will have symptoms.
Several ways. The actual findings are seen by a ct scan or MRI typically. It occurs in 20% of people over 60 & there may be no symptoms. Symptoms are a way of making a clinical diagnosis with pain, fatigue, numbness or tingling in the leg or legs and even back with standing and walking relieved by bending forward or sitting. As this is an age related process typically, there can be also some vascular issues.
See below. . A detailed history, physical exam, and then radiologic studies including an MRI us the most common way.