In the past, taxpayers weren't required to pay Medicare tax on income generated from investments such as capital gains, dividends, and taxable interest. Since 2013, however, you could owe a 3.8% Medicare tax on some or all of your net investment income (as part of the Affordable Care Act).
Restless legs syndrome (RLS) is a neurological disorder characterized by uncomfortable leg sensations that can interfere with resting or falling asleep. Experts believe that low levels of iron in the brain may be responsible for RLS. An imbalance of dopamine is also believed to be involved.
Some mental health medications can cause leg tremors. A thyroid gland that isn't functioning properly may be the cause of leg tremors. A person may be more prone to tremors while fatigued. Leg tremors caused by issues with the central nervous system can often be treated by medication.