Fatigue is the most daunting of multiple sclerosis symptoms. Patients can feel exhausted because of depression or because their symptoms rob them of sleep. Side effects of medications can worsen fatigue; so can the extra energy required for daily tasks. Researchers have even identified a type of fatigue -- known as lassitude -- that is unique to those with MS. It’s more severe than normal fatigue, occurs daily and can even greet you in the morning after a good night’s sleep. Fortunately for those with MS, there are as many ways to boost energy as there are causes of fatigue. Here are seven, from the National Multiple Sclerosis Society.