No. A strain is damage to a muscle or tendon, usually from a forceful contraction, such as a pulled hamstring. A sprain is damage to a ligament, the tissue holding two bones together, usually from a joint being forced past its normal range. The words are often used interchangeably, but the two tissues heal at different rates and need different rehabilitation, which is why the distinction matters.

There are four overlapping stages. Bleeding lasts a few hours. Inflammation runs for roughly the first two to three days and brings the swelling, heat and pain. Proliferation follows, where new tissue is laid down over several weeks. Remodelling then strengthens and reorganises that tissue, and can continue for months. Loading matters most in the last two stages, because tissue adapts to the demands placed on it.

All three increase blood flow to the area, which can increase bleeding and swelling while damaged blood vessels are still sealing. More swelling usually means more pain and slower early progress. Heat packs, hot baths, alcohol and deep massage over the injury are best left until the acute stage settles. Gentle movement away from the injured tissue is safe and encouraged.

No. Delayed onset muscle soreness peaks 24 to 48 hours after unfamiliar exercise, affects a whole muscle group on both sides, and eases with light movement. A soft tissue injury usually starts in a single moment, sits over one specific spot, and often comes with swelling, bruising or weakness. Soreness that is sharp, one-sided or stops you loading the limb deserves an assessment.

It can. Repaired tissue is not identical to the original: it is often less elastic and less well organised. If an injury heals without the joint regaining full range, strength and control, that area tends to be re-injured or to overload nearby structures. Progressive loading during the remodelling stage helps the new tissue align and tolerate force, which is why rehabilitation continues past the point where pain stops.

Fluid pools in the injured area while you are lying still overnight, and the tissue cools and tightens. That combination makes the first movements of the day feel worse. Morning stiffness that eases within 15 to 30 minutes of gentle movement is normal early on. Stiffness that is getting worse day on day, or lasting most of the morning, is worth reviewing.