If any of the above statements do apply to you, talk with your doctor before you become more physically active. Tell your doctor your intent to exercise and which of the above statements you selected that apply to you.
If you honestly reviewed all of the above points and didn't select any of them, you can be reasonably positive that you can safely increase your level of physical activity gradually.
If your health changes so that any of the above statements apply to you, seek guidance from a physician