What is McArdle’s Disease?

What is McArdle’s Disease?

McArdle’s Disease is a metabolic disease affecting skeletal muscle. It is also known as Type V glycogen storage disease.

An Overview of McArdle’s Disease

McArdle’s disease is a rare muscle disease affecting approximately 1 in 100,000 people. Because their muscles cannot properly metabolize energy, individuals with McArdle’s disease may experience fatigue and failure during strenuous activities like jogging, swimming or even walking. These episodes can result in painful cramping injuries that require medical attention. McArdle’s disease is an inherited condition, and is caused by a missing or non-functioning enzyme needed to make glucose for energy. While this condition imposes significant physical limitations, it is not directly life-threatening and with the proper precautions and lifestyle management, people who have McArdle’s Disease can live healthy, active lives.

About This Website

This website, mcardlesdisease.org, has been created to increase awareness of this rare condition. This site contains two types of content: general information and links about McArdle’s disease, and McArdle’s disease blog articles from individuals with the disease describing subjective experiences with the condition.

Be Sociable, Share!

387 thoughts on “What is McArdle’s Disease?

  1. Alex

    Im 21 and was diagnosed with McArdle’s disease last year. I was wrestling around and after I couldnt move. I layed in bed for 4 days without my kidneys working. I went to the hospitol and i had complete reno failure and rabdomylosis. I was in the hospitol for 3 weeks and went threw 2 weeks of dialysis. The doctors told me i had mcardles disease.

  2. June

    If you are anything like me, you’ve always known something was wrong but all the doctor’s thought you were nuts or lazy. I was finally diagnosed this year when after a few minutes of riding my bike, my legs swelled massively and I began urinating a very dark brown color. I went to the hospital and my kidney’s had failed. I was in the hospital for 2 weeks and also had dialysis for 1 week. I’m 26 and am relieved to finally have a diagnosis to be able to tell people what is actually wrong with me. I’m looking for a support group to be able to talk with people like me. I’m especially interested in anyone who has been pregnant and how their McArdle’s affected that experience.

  3. Clayton Blake

    I was diagnosed with McArdle’s Disease 2 years ago at 25. In 2003, did my morning exercise routine and woke up the next day unable to move. Spent 2 weeks in the hospital on that trip then had another episode in 2005. This time spent 3 weeks in the hospital, same symptoms. Doctors diagnosed me with chest wall pain accompanied by rhabdomylosis which didn’t fit. After talking to a neurologist and numerous doctors visits, the right diagnosis was made. Any one know of a research group for people like us?

  4. Tammy

    I was diagnosed with MCArdles disease March of this year. I have struggled with pain and fatigue since I was 14. Being adopted no one knew what I had. In fact they thought it was depression. Finally, at age 37 I had a doctor who believed me and decided to do a muscle biopsy. This is how I was diagnosed. Its comforting to know I am not crazy and now I know how to deal with it. I have 4 children and dont have time to be fatigued. So I run regularly to keep my strength and energy up. As far as my pregnancies and McArdles the first trimester I was extremely fatigued after that I felt better than I can remember.
    I was wondering if anyone experiences greater fatigue, pain, and swelling during the summer?

  5. Tayler

    Tayler is my 17 year old daugher who has had bouts of episodes from playing High School Volleyball for the past year. She has had 3 episodes of extreme muscle cramping from head to toe. 1 of which sent her to the ER. She also had a seizure in Sept. She is unable to walk for anywhere from 24-72 hours depending on the length of the episode. We have just spent the last week at MAYO, and she will have a muscle biopsy probably sometime in January. McArdles disease is what they are currently looking at. Please keep writing as the above information is VERY helpful. Thanks, Jodie

  6. Stephanie

    I’ve known all of my life that something was wrong with me. I was never able to run and walking uphill or upstairs was always difficult. The severe muscle cramp episodes that stay for three days and are excrutiating, started in my early 20s and have been getting worse ever since. I was diagnosed in 2004, after another painful episode in my thighs (after a yoga session) and focused research. Since then, just knowing what it is and understanding the bio-chemistry has been very helpful in dealing with the disease. Right now, my left foot is cramped up because I tried to wriggle my foot into a boot yesterday. I try to live life as normally as possible, but there are limitations. I’m also very interested in how sufferers deal with pregnancy. It’s so nice to be reading about other people’s experiences with the disease. Isn’t it frustrating how slowly the research is moving along? I really wish there was some more effective way to ‘loosen up’ the cramps…some more immediate relief. The pain is so bad that the strongest pain killers don’t work. Best of luck to all of you!

  7. Stephanie

    Hi, I am a mum of a McAdles child albeit she is now 30yrs.
    To your question relating to energy in the summer months. Kerry has always functioned better when the its warmer(not very often in UK) in fact she lived for 2 yrs in Cyprus and I was amazed at all she could do there.
    Winter here is a completely differant matter. She struggles to the most basic daily tasks that us non McArdles take for granted. It makes me very sad.

  8. Ben

    Tammy :
    I was wondering if anyone experiences greater fatigue, pain, and swelling during the summer?

    My symptoms always seem to be exacerbated by colder weather and my suspicion is that this is related to blood circulation. Blood circulation is inhibited by colder temperatures. Daily aerobic exercise(brisk walking) has helped me deal with this.

  9. allie

    I also suffers muscle cramps/back pain especially at my lower back since i was young but become worst this time (i am 37 yrs old now). There was an incident that i can’t stand up if i’m lying down. I can’t even move. My doctor just give me myonal and arcoxia… he also give me neurofenac- vitamins. How to check if i have this mc ardle disease. I want to exercise to trim me down but i am suffering from back pain. I can;t drive properly since my lower back is very painful.

  10. Site Admin Post author

    Allie – for your doctor to rule out McArdle’s disease they’ll likely do the ischemic forearm test or a muscle biopsy, both of which are described in item 3 at the top of this page, “Diagnosis of McArdle’s Disease.” This website contains links to other helpful McArdle’s disease websites which your primary physician may find useful. Best of luck.

  11. S2

    Not too long ago I found out about this disease and I am pretty sure it’s what I have. I turned 20 this year but I’ve had the cramps after running at school athletic days since I was 13. And the cramps aren’t the type where you can stretch your muscles out, it hurts extremely if I even try to move or rub gently the affected area and when they come it hurts enough to give me a jolt. It’s great to finally find a name for something in which I have very similar symptoms to and read about all I can from all your comments. Thank you!

  12. Shannon

    My daughter is now 18 but had her first flare of McArdles at age 14 with acute renal failure after a softball game. She has always complained with her legs hurting after walking short distances since the age of 2 1/2. The doctors would tell me she would grow out of it. Not to carry her, she would “toughen up”. She continued to dance-ballet, tap, and jazz, cheer, gymnastics, play golf and softball. Until this happened. This really limited her. She did continue her golf and softball career for a couple of years after this but it was such a struggle for her. She missed a lot of school because she was in and out of the hospital so much with such severe muscle pain. It effects her back, thighs, and calves mainly and when it gets really bad her upper arms. She had a muscle biopsy to learn she had McArdles and a year later we went to see Dr. Slonim in New York. He gave her an exercise regimen and started her on Alanine four times daily. I thank God for that man. I don’t know where we would be today if it wasn’t for him. Whatever you do, do not do the sucrose load before activities, please. That is the worst thing you can do. We did that for about a year before we saw him and we took some huge steps backward. My daughter has trouble sticking to her routine of exercise sometime and staying motivated. Is there anyone else out there like that? It seems that when she gets going really good, she ends up in the hospital again and gets upset about this and feels like it isn’t helping her situation. She also has trouble with vomiting alot with her McArdles. Does anyone else. This kind of threw Dr. Slonim off a little bit when she saw him. She does have one of the more severe cases he said. Winter (colder) weather is harder on her. Please, someone respond and tell me how I can keep her motivated. She is in college now and I don’t know whether she is really exercising daily or not. I am trying to get her to respond to a support group such as this, to be able to talk with others who have the same thing she has and experience some of the same things she has gone thru would be great for her I think. She says her friends really don’t understand her sometimes, why she feels like she does, but to “talk” to someone who does would be great I think. HELP!!!

  13. Site Admin Post author

    There is a Facebook group of people with McArdle’s disease, click the link on the righthand side of this page. Getting in touch with many other people who share similar challenges can be helpful. There does seem to be a lot of variation in the degree to which people experience difficulty. The symptoms of this disease are exacerbated by secondary factors like cardiovascular conditioning, general level of physical activity and lifestyle, diet, and hormones. Some people find it almost debilitating, but others are somehow able to remain active and the disease doesn’t slow them down too much, and there’s no explanation for it yet. First things first, join the Facebook group.

  14. Shannon

    Thank you so much. I have shared this website with her. She has read the letters from others with McArdles and realizes they all pretty much share the same story. She went on to Facebook and joined the group. Thanks again. Is there any research out there for an enzyme replacement?

  15. Shannon

    In an effort for those of you with McArdle’s to avoid complications when undergoing surgery, please get a MedicAlert bracelet stating you have a muscle enzyme deficiency. My daughter wears one all the time. You never know when an emergency will occur (car accident, etc) and I may not be able to get to her and she may not be able to tell them she has a muscle disease. The wrong anesthesia can kill McArdle’s patients. THIS IS VERY IMPORTANT!!!! Hayley had 3 surgeries before we knew she had this and we consider ourselves very, very lucky. When Dr. Slonim explained what could happen in surgery, it really scared us.

  16. Janie

    I have just discovered this site and am surprised there is such a one! It’s nice to know I’m not alone in the world.
    I was diagnosed in 1978 from a biopsy at Univ. of Md. Hospital. At that time I was the 2nd case in nine years. Several years ago I saw Dr. Slonim in NY. I have to say the results for me, were less than stellar. that’s not to say, it might not be helpful for others; I guess I had very high expectations.
    I have been reading people’s posts and noticed no one mentioned having an extreme amount of trouble with hypoglycemia. Mine can bottom out very quickly eventhough I eat a high protein diet.
    In high school I used to push myself to keep up in gym and walking to the bus etc. Beside the muscle rigidity and heaviness in my legs, I would begin to lose my vision and see bright swirling spots on a black background, which actually caused me to be unable to see where I was going. I would always be incredibly thirsty and after drinking would get very nauseated. I don’t push that hard anymore, so don’t have that trouble very often. I just wondered if anyone else had that problem.
    Also, does anyone else totally and completely stiffen up under stress…like having to run in an emergency? I have had the worst cases of myogloburnia afterward with extreme pain causing me to be hospitalized. It’s one of the worst parts of this whole syndrome…not being able to act in an emergency.

  17. Site Admin Post author

    Hi Janie, glad you found the site. Nope, you’re not alone and rather far from it.

    Hypoglycemia seems to be pretty common with people who have McArdle’s disease. Muscles are forced to look outside the cell for a source of energy, so blood sugar can drop abruptly. If you are aware of this and prepare in advance by having the right snacks with you (low-glycemic index foods like granola bars may be good) you can mitigate this by taking a break when you feel the onset of low blood sugar.

    Continue to visit this site and be sure to join the Facebook group (the link is on the righthand side of this site.)

  18. Brandi Lightsey

    @Clayton Blake
    Clayton, I was diagnosed at age 24 by Dr. Ronald Haller in Dallas, Texas. He is a Mcardle’s specialist and have completed 2 research studies with him. One in Dallas and one in Copenhagen, Denmark. He is associated with UT Southwest and Presbyterian Hospital.

  19. Victor Kowal

    Found your website while searching for info on McArdles. I’m 48 from Sydney Australia and have been diagnosed with a glycogen storage disease from a biopsy 3 months ago which showed vacuoles in the tissue. The doctor has diagnosed McArdles subject to a ischemic forearm test to confirm.
    I have constant pain in my calves, thighs and upper arms. Can anyone advise if this is symptomatic of this disease? The pain never fully goes away and is getting debilitating. Painkillers only work so much. Is there anything that can help to keep the aches at a bearable level.

  20. Denise i Frias

    I’m a 33yr old mom of 2 boys I had my boys at a very young age before I knew I had McArdel’s I wasn’t diagnosed til 2yrs ago Its been kinda scary knowing something is wrong wit me I’m especially concerned now abt haveing more children but I just try to be mindfull of what triggers this illness&avoid it as much as poss. but do eat a lot of sweets so that I find gives me the extra energy I need…

  21. Christopher

    I am a 37yr old male and was diagnosed 17yrs ago after a two week stay in the hospital. I was glad to know that I wasn’t just lazy after dealing with the symptoms since the age of around 5 or so. It’s nice to see this website up because back then there was little to no information on this. I have figured out by trial, error and a lot of pain what I can and cannot do over the years so I want everyone to know that we still can have an active life. I won’t tell you that it’s still not frustrating when people look at this 6’4″ 275lb man and wonder why he can lift weights or run around and a pain the the you know what dealing with it, but we can do it. I did a 5k run/walk or should I say walk/jog last year, pulled an airplane for United Way (I STRONGLY advise against that one!) and recently joined the YMCA. I have learned to take it easy and let all those around me know that I have this condition that requires me to take it slow. Only my 4yr old daughter doesn’t understand why daddy has to go so slow! :-) My 15yr old son knows about and understands (he still can’t beat me in a game of 1 on 1 basketball.) Anything that requires a burst of speed (ie baseball) or strength, stay away from! I still hike, but I go very very slow if going uphill, taking rest breaks along the way and use a big stick to help me walk. When riding my bike, I try to stay away from hills or I walk the bike to the top otherwise on flat surfaces I just again, GO VERY SLOW. If i get in the pool, I just play around because swimming uses more muscles that I originally realized. For basketball I don’t run a full court game, just half court and I stay away from the young guys who think they are Jordan! The treadmill is where I get most of my exercise. I found this site looking into the “Sucrose intake” and the B6 supplements before exercise to help me but I’m not sure which direction to go. I am not a doctor, don’t play one on tv and didn’t stay in a Holiday Inn Express last night. I just have had a lot of experience dealing with this. Hope it helped.

  22. HayleyJ

    Victor, my name is Hayley and I was diagnosed with McArdle’s about 4 years ago. I am 18 and have been able to control the symptoms with moderate excercise and an amino acid called Alanine. I was diagnosed after a muscle biopsy. I have had symptoms all my life but my doctor’s said that I was just lazy and that I would grow out of it. When I was fourteen I was hopitalized with rhabdomyolysis and acute kidney failure. My doctors were terribly confused becuase most cases of rhabdo are in people who do heavy labor on a daily basis. As for your pain I also have severe pain in my thighs, calfs, upper arms, and lower back. When I am hurting I try to strecth lightly and take children’s ibuprofen. Also I have found that drinking plenty of water and staying away from caffiene helps to keep my muscles hydrated and reduces the pain. As for the exercise you might try walking for 10-15 min. at 1.2-1.5 mph. Make sure you don’t over exert yourself though. I am being treated by the formost McArdle’s specialist in the world, Dr. Alfred Slonim. He is based in New York. If you would like to contact him just type his name in on Google and his contact information will be on one of the sites, not sure which one though. Keep me updated and I will try to help as much as possible.

  23. Stephanie

    Hi Christopher, i have tried yoga many times and finally gave up on it. I felt too awkward sitting out the “bad” poses and stopped yoga. The Warrior pose is one of them. It requires you to be in a prolonged squat. That has caused some of the worst episodes for me and put me out of commission for three days on end, each time. I’m sure there are some McArdle’s sufferers who can do it, but I would be very careful. On the other hand, some of the stretching exercises in yoga have been wonderful for my flexibility and loosening of muscles. I often miss it, but right now swimming (breast stroke and back stroke, mostly) as well as walking (or the elliptical machine) have been the best exercises for me.

    I have read on another message board that women with McArdle’s have felt their best during pregnancy because the fetus supplies them with the enzyme they lack. Is there any literature on this? Can anyone tell me more? What were you able to do, that you couldn’t do before?

  24. Luke Post author

    Christopher – almost anything, including yoga, can cause rhabdomyolysis. People with McArdle’s disease can hurt their muscles doing the most mundane activities healthy people take for granted, like carrying a child in their arms, or craning their neck to look at something, or even crouching in an uncomfortable position.

    I don’t want to make it sound like anyone with the disease should avoid physical activity, however, because a sedentary lifestyle may present the biggest threat of all. An inactive lifestyle with little physical activity acclimates the body to having no demands placed on it, which only increases the risk of muscle failure during what should be “normal” activities. Avoiding injuring your muscles demands a vigilance that is itself very fatiguing, and you often don’t realize you’re in any danger until it’s too late and the damage is done.

    Here’s a link to a study on the benefits of cardiovascular exercise in McArdle’s disease. The website requires free registration to view the full research PDF, but it is encouraging data.


Leave a Reply to Clayton Blake Cancel reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>