How did the pain start- suddenly/gradually? Duration and intensity needs to be known. There are.muscles, ligaments which may be injured while gymming. You need to consult a good physiotherapy so that cause is identified and treated. Also, you will need to be guided about weights before you resume weight training especially if you wish to keep lifting heavy weights and still be paimfree. Therapist will guide you about which muscles, what amount of weights , volume and frequency