It seems there are three questions, atrial fibrillation, a general sense of fatigue and bruising. One and two may go together and I generally start my investigation along those lines. Sleep apnea is a common problem. It is often present in people who are overweight, particularly those who snore. If you are very tired in the morning, sleep easily during the day and snore loudly, you may have sleep apnea. Sleep apnea may cause or worsen high blood pressure. Outside of underlying heart disease, Sleep Apnea is one of the most common causes of atrial fibrillation. Discuss this with your doctor and consider having a sleep study. The bruising requires more information than we can get here. We can t count your spleen but we can measure blood counts and clotting proteins. That is the place to start.