Tylenol (acetaminophen) can be bad for you mainly due to its potential to cause serious side effects if taken in high doses or for a prolonged period. The primary risk is liver damage, which can be severe enough to require liver transplantation or cause death. Overuse or overdose can also lead to symptoms like nausea, vomiting, abdominal pain, jaundice (yellowing of skin and eyes), sweating, and in extreme cases, coma. Other possible side effects include kidney damage, gastrointestinal issues, skin reactions, and allergic responses. It is important to follow dosing instructions carefully to avoid these risks and not to exceed the recommended daily limit of acetaminophen, which is generally 4000 mg per day for adults. Also, avoid taking multiple medications containing acetaminophen simultaneously and be cautious if consuming alcohol. Elderly people may have a higher risk of side effects due to reduced liver and kidney function. If symptoms of overdose or allergic reactions appear, medical attention should be sought immediately.