Everyone feels stressed from time to time. Not all stress is bad. All animals have a stress response, and it can be life-saving. But chronic stress can cause both physical and mental harm.
There are at least three different types of stress:
Different people may feel stress in different ways. Some people experience digestive symptoms. Others may have headaches, sleeplessness, depressed mood, anger, and irritability. People under chronic stress get more frequent and severe viral infections, such as the flu or common cold. Vaccines, such as the flu shot, are less effective for them.
Some people cope with stress more effectively than others. It's important to know your limits when it comes to stress, so you can avoid more serious health effects.
NIH: National Institute of Mental Health