I have been suffering with pains in my knees for a long time now but recently i am having difficult getting up stairs can u advise not seen my g.p?

Tendinitis: You may have tendinitis or severe arthritis. Best is to get examined by pcp and see what they recommend. cortisone shot, ortho consult, physical therapy?

Knee pains: Your struggles are likely the progression of likely arthritis in the knees & is typical. There are exercises that you can do to help improve the strength & flexibility of the joints, of which could improve your pain as well as your ability to navigate stairs. This is a form of physical therapy. Also using Motrin or Aleve, (naproxen) if tolerated, can help with the pain. If worsens, you should see your doc.