Mild chest pain mostly with movement/laughter, some radiates to arm/neck, improves when resting, tender spot around sternum. been working strenuous night shifts a lot, poor sleep, & not the most fit. breathing fine, pulse fine. safe to continue work?

From what you described you may continue to work. Your symptoms suggest deconditioning of muscles and regular aerobic exercise would help. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV, Flu and Covid vaccines. Wish you good health!

Your symptoms are consistent with costochondritis, an inflammation of the joint between a rib and the sternum. It is treated with avoidance of any activities that stress that joint and, if you're able to take them, anti-inflammatory meds like ibuprofen or naproxen according to instructions, for a week or so. Warm compresses & rubbed in liniments like BenGay offer relief . See your MD as needed.