Shoulder pain doing push up

RICE Method. Not something to mess around with. Unless you don't mind months of recovery.

You rest until it doesn't hurt any more. A few weeks isn't going to set you back too much.

If you want to give your shoulder a chance to heal on its own, you have to do absolutely NOTHING that involves any shoulder movement.

If you continue to work the shoulder because you're too stubborn or impatient to let it rest, you will just prolong the recovery time and/or possibly injure the shoulder further.

I've had 2 rotator cuff surgeries and the shoulder pain leading to the surgeries never went away until I had the surgeries, healed and completed physical therapy, a process that took a year for each shoulder.

If it takes you as long to get an orthopedic appt as it does me, you should schedule an appt NOW to get an MRI, if the pain doesn't go away on its own. If the pain goes away b4 the appt is scheduled, you can just cancel the appt.

PS: Muscle imbalance does not cause shoulder pain. Muscle or ligament strains and/or tears do.

Shoulder pain during a push-up is either indicative that you injured it doing something else or you need to really assess your form during a push-up. As everyone already stated, you should be implementing the RICE or PRICES method to allow for proper healing. Being in a deficit isn't going to do you any favors since being injured is catabolic in itself since tissue has been damaged, so eat at maintenance or a slight surplus, focusing on proper protein intake.

Running might be okay but 1) running is a catabolic movement, 2) the jarring from running *may* cause referred pain, just pay attention to pain, and 3) running will get you better at running > your shoulder health won't see improvement from doing a completely different body part.

Alternatives: if you want to remain active, strength training to tolerance that stimulates muscle protein synthesis -
even if it's lower body, like leg press/curls/etc or another body part - might be better to promote signaling for repair. For upper body, limit it to what you can do with range of motion and resistance bands may be beneficial. It's better to pulse lighter weight/resistance for rehab/mobility for higher reps more often throughout the day than to do one long heavy session.

Source: Optimal Nutrition for Injury Recovery - Lyle McDonald

I had rotator cuff (RC) surgery in both shoulder and the left one never healed completed even with proper follow-up PT. I developed a frozen shoulder and it took me more than 18 months to get almost back to normal. That was almost 8 years ago.

For the last 12 months the pain had returned and a cortisone injection didn't do much help. The MRI showed increase OA, tendinitis, and a small bone spur. The pain is real and it flares up out of no where, which is most likely the result of the OA (very common after RC surgery).

My orthopedic doctor (also the Director of the Sport Clinic), reviewed my workout and strongly recommended a total change. I can't bench press in supine position so I had no choice but to use the sitting press machine. No OHP or any other exercise that involves lifting the arms above shoulder level. I can't do dips, not even using the dip machine due to the pain. And I can go on and on about how I had to modify my workout to avoid further shoulder injury and pain.

Most likely I aggravated my left shoulder by trying to go heavier on my lifts without considering my problem and the fact that I am a small and much older person. Hard to admit that ego, too much self confidence and the fear of losing what I had gained in muscle strength and definition, got in the way of common sense. I am paying the price.

I know how hard is to modify our fitness routine to accommodate injuries or limitations. But it is better to do something else, rest, listen to our bodies and bite the bullet rather than ending in the OR.

As other said, ice, rest, walk and if the pain continues go to your doctor and ask for a X Ray. Some insurances don't allow a visit to an specialist or to a physical therapist, unless is requested by the primary physician.