Pulled muscles.

Sprains.

Tendon and ligament tears.

Vertebra damage from lifting too fast or incorrectly.

Falls. These are usually life altering.

Not using PPE because it takes too long or impedes your vision or it causes you to sweat more or you just don't want the rest of the crew to call you a pussy.

Hearing damage (because no PPE).

Cuts and bruises because you didn't wear gloves.

Sunburn every day which means skin cancer is guaranteed eventually.

Long term exposure to stuff like concrete dust, fiberglas insulation, sawdust from treated wood, volatile organics etc which can wreck your lungs.

Poor nutrition because of too-short lunch breaks and unavailability of non-processed food.

Getting ripped apart by heavy powered equipment because you were in the wrong place at the wrong time and somebody did something stupid. Again, life altering.

Frequent alcohol use to ease the aches and pains built up during the day.

But mostly just hard damn physical activity in brutal conditions 8-12 hours a day. Do this for 20 years and it ages you fast and wears out your body.

This is not exercise at the indoor gym with safe equipment under the supervision of a coach. This is "get your ass up that ladder with 100 lbs of shingles on your shoulder without a stinking safety rope and fast, or you're fired."

What about OSHA? OSHA on construction sites is not really a thing I've seen, and if anybody mentioned an OSHA violation they would probably be fired. And since much of the labor force is undocumented, they ain't gonna report a violation anyway, lest they get discovered and deported.