AS is a type of inflammatory arthritis that can cause bones in the spine to fuse over time, according to the Mayo Clinic. This process makes the spine more rigid and may affect a person’s posture. “I do have upper neck stiffness. My knees were problematic a couple of years ago but are under control now,” explains Lovaine Cohen, an AS patient, advocate, and health and wellness coach. “Fortunately, AS doesn’t slow down what I need to accomplish on a daily basis because I refuse to let it do so.” Part of Cohen’s regular routine includes drinking plenty of water, especially during the hot-weather months. “I do notice some swelling in my feet or knees in the humid weather,” she says. “I notice more stiffness in my body when I’m not drinking enough liquids." Here’s what you should know about how proper hydration can help your AS symptoms.

Why Dehydration Might Affect Someone With Ankylosing Spondylitis

Because AS is an inflammatory disease, any type of stress on the body can worsen symptoms, according to the Spondylitis Association of America. “People with AS tend to be a little more sensitive to certain stressors, and getting dehydrated can certainly be one of those,” says Hillary Norton, MD, a rheumatologist at Sante Fe Rheumatology in New Mexico. “Anything, whether it be mental or emotional stress, physical stress, all of those things can really affect the immune system and cause additional flares, additional disease activity, when you have something like AS.” Dr. Norton, who has AS herself, is in a unique situation to help her patients manage the same disease she’s living with. “There’s nothing like having something yourself to help you understand what your own patients are going through,” she says.

Water Helps Joints and Bones

Although medical literature on the link between hydration and AS is scarce, doctors do know that adequate hydration can help keep joints and bones in good shape. “To my knowledge, I don’t know of any studies specifically on dehydration and AS, but I will say that in my clinical experience, stressors of any kind can certainly trigger the onset of disease and negatively affect someone with AS,” says Norton. According to the Arthritis Foundation, staying hydrated is important for flushing toxins from the body, which could lower inflammation. Water also helps your body create synovial fluid — the layer of liquid that cushions joints and prevents friction with movement. And proper hydration is also vital for maintaining healthy cartilage — the tissue that lines your joints. Even your bones are comprised of 31 percent water. Drinking enough water can keep bones healthy and act as a shock absorber for the brain and spinal cord. “If someone is mildly dehydrated, that can cause fatigue. It can cause brain fog. It can cause muscle cramping, and when we have a flare, we can certainly have symptoms like this,” she says. “It can get a little bit complicated if you get a little bit dehydrated. Is that from dehydration, or is it from the AS? So you start to wonder about those symptoms,” says Norton. The Mayo Clinic defines dehydration as using or losing more water than you take in so that your body doesn’t have enough fluids to carry out normal functions. According to the Cleveland Clinic, common signs of dehydration may include:

HeadacheConfusionFatigueDizziness or lightheadednessWeaknessDry mouthMuscle crampsFlushed skinChillsHigh heart rate combined with low blood pressureLoss of appetiteConstipationDark-colored urineThirst

AS Medication and Dehydration

Certain medicines may leave AS patients more vulnerable to the effects of dehydration. “If people are taking NSAIDs [non-steroidal anti-inflammatory drugs] for their AS and they get dehydrated, that can be dangerous for their disease,” says Norton. NSAIDs, such as ibuprofen (Advil, Motrin) and naproxen (Aleve), as well as others available by prescription, are commonly used to treat symptoms of AS.

How Much Water Should You Drink?

There aren’t specific hydration recommendations for people with AS, but the National Academies of Sciences, Engineering, and Medicine suggests the following:

Adults who are female should consume 2.7 liters (L), or about 11 cups, of total water per day.Adults who are male should consume 3.7 L, or about 16 cups, of total water per day.

These measurements refer to total water intake, which can come from both beverages and the foods you eat. The Spondylitis Association of America also warns that drinking more than two alcoholic beverages per day increases a person’s risk of developing weak bones. Alcohol can also cause adverse reactions when consumed alongside certain medications.

Tips for Staying Hydrated With AS

Some simple tricks can motivate you to drink water at regular intervals throughout the day. “I always keep a glass or bottle of water on my nightstand. When I get up in the morning, the first thing I do is take a few sips to ensure I’m getting my day off to a good start,” says Cohen. She also explains that the bottle she drinks from can encourage her to stay on track. “Sometimes I like to drink out of a large mason jar, instead of a glass. It can hold more water at a time and makes drinking water more fun.” Other tips for staying hydrated include:

Add flavor to your water. A squeeze of lemon or lime can liven up a plain glass of water.Try a tracking app. Apps like Daily Water Free or Daily Water can help you log your fluid intake.Use a measured bottle. Water bottles with measuring markings might be useful tools.Set an alarm. Try setting an alarm on your phone to alert you that it’s time for some fluids.

The Bottom Line About Water and AS

Drinking enough water is important for anyone, but it’s crucial if you have an inflammatory disease, such as AS. Water keeps joints and bones healthy and lessens inflammation, which along with a healthy lifestyle could improve symptoms. “I just tell my patients that in addition to the medications that we use, everything else that we do is important for keeping us healthy, and hydration is certainly one of those things that we have to be cautious about," says Norton. But moderation is key. Although rare, drinking too much water could potentially lead to a serious medical condition called hyponatremia, which causes the sodium in your body to become diluted. Talk to your rheumatologist or a dietician if you’re not sure about how much water you should be consuming.