It totally varies from person-to-person. Some get no symptoms at all whereas some experience very strong symptoms. I personally, have very less symptoms during my cycles.
I have a friend who gets severe stabbing abdomen pain every time she has her periods. She rolls on her bed cries the whole time, vomits everything she eats and her flow is too heavy every time. Somebody needs to be home to take care of her when she is unwell, it is so stressful for her and her family. She has seen many specialists; it is just that, the symptoms are too strong. Even pain-medications don’t help too much.