context: Multiple sclerosis ( MS) and Guillain- BarrÃ© syndrome ( GBS) are diseases of the nervous system. They're not the same, but they do have a lot of similarities. Both MS and GBS are autoimmune diseases. This means they cause your body's immune system to attack its own tissues. They both start when the immune system attacks and damages something called myelin. That's a layer of insulation that surrounds nerves. It also helps nerves transmit their messages. Each condition affects a different part of your nervous system: MS damages the central nervous system. That's the brain and spinal cord. GBS damages the peripheral nervous system. That's the nerves outside the brain and spinal cord. They help the central nervous system communicate with the rest of your body, including the skin, heart, and muscles. Chronic inflammatory demyelinating polyneuropathy ( CIDP) shares many of the same symptoms as GBS, but CIDP lasts much longer, and if not caught early enough, can cause lasting damage. It's very rare for someone to have MS and GBS at the same time. But it has happened. Experts say it may be a coincidence. But both diseases share causes that might trigger them together. Doctors don't know exactly what causes MS, GBS, or CIDP. But they have a few ideas. GBS often starts a few days or weeks after an infection like the cold, flu, or stomach illness. Recently, experts have seen a rise in the number of people with the mosquito-borne Zika virus who also have GBS. The bacteria or virus that triggers GBS may change cells of the nervous system in a way that makes the immune system think they're attackers. A few people have developed Guillain- BarrÃ© syndrome a few days or weeks after a vaccination. CIDP starts much like GBS but as the disease progresses, the myelin which protects the nerves is damaged or removed entirely, causing nerves to either function abnormally or stop working altogether, With MS, a few things might be at play, including: Infections, such as from the Epstein- Barr virus, herpes, or Chlamydia pneumoniae Genes Too little vitamin D Smoking MS, GBS, and CIDP each affect nerve signals. Common symptoms of both include: Weakness Numbness Tingling in the arms and legs GBS symptoms usually start within a day and spread from the legs to the upper body. Unlike GBS where symptoms eventually ease and patients can recover, CIDP progresses and patients could have permanent disabilities. MS often starts in a few days, but sometimes symptoms don't show up for a while. The numbness from MS usually isn't severe. But the condition can also cause: Bladder problems Dizziness Fatigue Pain Tight muscles Trouble speaking and swallowing Vision problems GBS brings weakness that may last years. People can become almost totally paralyzed. The paralysis makes it hard to breathe and swallow. For CIDP, symptoms are the same as GBS as is most often marked with difficulty walking and symptoms progress longer. Medicines that slow MS and prevent flare-ups include: Alemtuzumab ( Lemtrada) Dimethyl fumarate ( Tecfidera) Fingolimod ( Gilenya) Glatiramer acetate ( Copaxone, Glatopa) Interferon ( Avonex, Betaseron, Extavia, Rebif) Mitoxantrone ( Novantrone) Natalizumab ( Tysabri) Ocrelizumab ( Ocrevus) Teriflunomide ( Aubagio) Doctors also prescribe steroid medicines to ease inflammation during MS flare-ups. The two main treatments for GBS and CIDP are: Plasma exchange: Blood is removed from your body. Plasma -- the liquid part of blood -- is separated from the white and red blood cells. Then the cells are returned to your body along with donor plasma or a plasma substitute. Getting rid of the plasma takes out antibodies. They are part of that immune system response that damages nerves. Immunoglobulin therapy: This uses an IV to deliver proteins the body normally uses to attack viruses and bacteria. That eases the immune system's attack on nerves. Still, doctors aren't sure how they work. MS is a lifelong disease. Although its symptoms can come and go, there is no cure. Some people have more frequent and severe attacks of symptoms. The future for people with MS has improved a lot, thanks to new medicines. Today, most people with MS are still able to walk 20 years after they're diagnosed. People with GBS can have severe symptoms, but they usually make a full recovery. GBS often gets better after a few weeks, but the weakness it causes can continue for years. Sometimes, the numbness and tingling will come back years after the first attack of symptoms. Early recognition is key to halting the progression of CIDP. Up to 30% of CIDP patients will progress to wheelchair dependence.