RELATED: If You Notice This While Walking, It May Be an Early Sign of MS. A 2021 study published in the Multiple Sclerosis Journal analyzed more than 200 MS patients the year after their diagnosis and found that the most common early symptom was fatigue. According to the National Multiple Sclerosis Society (NMSS), nearly 80 percent of people diagnosed with MS experience unexplained fatigue early on. People with MS can have multiple types of fatigue, like sleep deprivation due to bladder dysfunction or nocturnal muscle spasms, or fatigue as a result of having to expend more effort just to accomplish daily tasks. But the NMSS says one type of fatigue, referred to as lassitude, is unique to people with MS. This kind of fatigue “generally occurs on a daily basis, may occur early in the morning, even after a restful night’s sleep, tends to worsen as the day progresses, tends to be aggravated by heat and humidity, comes on easily and suddenly, is generally more severe than normal fatigue, and is more likely to interfere with daily responsibilities,” according to the organization. RELATED: Selma Blair Reveals the First Sign She Had Multiple Sclerosis. Fatigue related to MS typically happens when nerves deteriorate in the spinal column, which tends to result in weakness that is most noticeable in the legs at first, per the Physio Centers of Africa. “Often people say that their legs feel heavy and they’re hard to lift,” Gloria Hou, MD, the medical co-director of the University of Washington Medicine Multiple Sclerosis Center in Seattle, Washington, told WebMD. “That’s a very typical description for neurologic weakness.” And for more health news sent right to your inbox, sign up for our daily newsletter. Fatigue is not the only symptom the majority of MS patients experience early on. According to a 2018 study published in the journal Temperature, around 60 to 80 percent of patients with MS also experience a particular kind of heat sensitivity known as the Uhthoff sign or Uhthoff syndrome. This is a condition in which even a minor increase in core body temperature of a quarter of a degree can temporarily worsen a patient’s neurological symptoms, causing MS patients to potentially experience enhanced muscle weakness, visual impairment, cognitive problems, imbalance, or even fatigue. According to the NMSS, other common symptoms of MS include the MS hug, which is a squeezing sensation around the torso; walking difficulties; numbness or tingling; stiffness; muscle spasms; vision problems; vertigo; dizziness; bladder dysfunction; sexual problems; constipation; loss of bowel control; pain; itching; cognitive changes; emotional changes; and depression. Other MS symptoms that may occur, but are less common among patients include speech problems, loss of taste, swallowing problems, seizures, breathing issues, and hearing loss.ae0fcc31ae342fd3a1346ebb1f342fcb Ultimately though, the disease can show up in different ways for everyone, so if something feels off to you, you should talk to your doctor. “MS symptoms are variable and unpredictable,” the NMSS warns. “No two people have exactly the same symptoms, and each person’s symptoms can change or fluctuate over time.” RELATED: This Was the First Sign of MS “Sopranos” Star Jamie-Lynn Sigler Noticed.