Pain After Exercise
If you are someone who exercises (everyone should exercise by the way) and you realize that you feel significant pain after exercising, not just muscle soreness but long-term pain and swelling, you should never ignore this. This pain might indicate temporary muscle or bone damage that can become permanent. If you have constant pains after exercise, try cutting down your workouts, and be sure to apply ice to the painful area. If the pain persists, go see a physician.
Severe Head Pain
This doesn't refer to normal headaches or migraines, but that 'worst pain ever' kind of headache with constant peaks within seconds or minutes. The headache becomes so intense that it not only affects your vision, but your mental functions. This isn't a sign you should ever ignore. It's advisable to go see a doctor for a checkup.
Losing Weight Without Trying
For most people, this is considered a blessing they embrace and even celebrate, but it is important to be careful when you notice this. Rapid or constant weight loss when you have done absolutely nothing and changed nothing in your diet, lifestyle, activity or exercise, can be indicative of an underlying health condition. You are better off not ignoring this and going for a medical checkup.
Always Very Thirsty
This could be normal for most people, but if you find out that you don't usually feel very thirsty and all of a sudden it's like you have to consume tankers of water to quench your frequent thirsts, it's another sign you should pay attention to. Particularly if the frequent thirst is accompanied by any swelling or rapid weight gain or if it's accompanied by nausea or fatigue, you should ensure you don't ignore this sign and go for a checkup.