Chronic fatigue syndrome is a disease marked by extreme tiredness.The signs of chronic fatigue go beyond exhaustion and can include insomnia, weakness, and memory loss.Chronic fatigue can be hard to diagnose because the cause is unknown.Here are the signs that you may be living with chronic fatigue.Chronic fatigue can make you feel so tired that it becomes difficult or nearly impossible to perform the activities expected of you each day. Though there are some days where we all feel overtired or burnt out, there's more to chronic fatigue than just feeling tired.Chronic fatigue syndrome is a debilitating disorder that affects an estimated 836,000 to 2.5 million Americans, according to the CDC. Many that suffer from chronic fatigue have not been diagnosed, likely because professionals have yet to identify a definitive cause, and there are no tests that clearly indicate a chronic fatigue diagnosis.As a result, a chronic fatigue diagnosis relies heavily on meeting criteria for a specific set of symptoms that go beyond feeling tired: Those with chronic fatigue may also suffer from insomnia, memory loss, dizziness, and frequent headaches.Here are the signs of chronic fatigue and what you should be looking out for:You're tired and sleeping more doesn't helpThe first symptom you'll likely notice with chronic fatigue is severe tiredness, as it usually occurs before other symptoms. According to the CDC, this noticeable symptom occurs for more than six months when chronic fatigue is to blame and is not helped by sleeping more.You find you are unable to perform daily activities that used to be simpleIf you're unable to go to work, get out of bed, eat, or drive because you feel exhausted, there's a chance this is a sign of chronic fatigue. Having chronic fatigue impairs your ability to perform usual activities of daily living for six months or more because of extreme tiredness.Trouble falling asleep or staying asleep is another signThough you feel so exhausted all the time, an interesting sign of chronic fatigue is being unable to fall asleep or stay asleep, a sleep disorder called insomnia. And if you do get some sleep, it often doesn't feel refreshing. You wake up feelingyou guessed ittired.When treating chronic fatigue, addressing insomnia first can be an important part of managing symptoms, so it's important to let your doctor know if you're experiencing it.A sore throat is a surprising, but common, signIf you're experiencing other symptoms, including prolonged exhaustion, a sore throat could point to chronic fatigue. According to the Mayo Clinic, swollen lymph nodes and a sore throat is another symptom.Difficulty concentrating or memory loss goes along with chronic fatiguePatients with chronic fatigue may feel confused, forgetful, and have difficulty concentrating, also known as "brain fog." Constantly feeling tired, in addition to poor sleep, makes it hard to focus, speak clearly, or remember words when you have chronic fatigue.Dizziness or weakness can worsen when sitting or standingIf sitting upright or standing worsens your symptoms, then this may be a sign of chronic fatigue. You may also feel lightheaded, dizzy, weak, or have blurred vision, according to WebMD.Headaches or migraines is present in 7% of people with chronic fatigueThose with chronic fatigue may experience frequent headaches or migraines. In a 2018 study conducted by Migraine in America, 7% of over 4,000 respondents who suffer from migraines reported being diagnosed with chronic fatigue. Additionally, about 80% of people said fatigue was one of their top migraine symptoms, along with difficulty concentrating and brain fog.Join the conversation about this storyNOW WATCH: What El Chapo is really like, according to the wife of one his closest henchman Click here to read full news..