Diagnosis is crucial in decision-making when treating a patient with shoulder pain. Ultrasound is also very important in the diagnostic and therapeutic pathway, especially when surgery is being considered. This article outlines the diagnostic pathway using the patient’s history, physical examination and ultrasound examination. It is important to correlate the clinical assessment with the imaging signs. It is also important to treat the patient and not the images as there may be abnormalities detected on imaging that are not symptomatic. The article covers the important diagnosis of subdeltoid subacromial bursitis, glenohumeral joint capsulitis, calcific tendinosis, acromioclavicular joint osteoarthritis and long head of biceps tendinosis. It will guide the reader in how to use the findings to treat, using ultrasound-guided injection and other techniques, including steroid injections, hydrodilatation, barbotage and extracorporeal shockwave treatment. These are discussed with the knowledge from over 30 years of experience with a literature review evidential support. I have included tips to make these procedures more effective in treatment and final outcome. There is discussion regarding the use of steroid injections in the presence of a rotator cuff tear and how to proceed if the patient has more than one disease process. The sensible use of steroids and local anesthetics are included, bearing in mind that lidocaine and high concentrations of long-acting local anesthetics are chondrotoxic and should not be injected into joints.