The final three minutes of my hour-long elliptical workout were not easy. Pain spread across my stomach, causing me to row in a half-sitting motion, and my chest vacillated between violent coughs and the sorts of deep breaths people take when they think they’ve seen a ghost. Perspiration fell from my shirtless torso to the garage floor. The amount of sweat was not the kind my body produces from exercise. This amount of sweat was from something else.

That “something else” was diabetic gastroparesis, an ailment that occurs when the stomach has trouble digesting food, which leads to debilitating pain, nausea, and diarrhea.

Two days prior, a new friend invited me to a brewery where he was spinning vinyl at 5 p.m. I stopped drinking alcohol four years ago, but I haven’t stopped enjoying a Southern California summer evening listening to records. That Thursday night, we ran four miles through his neighborhood, and after our jog, I entered his abode to meet his wife, but I shouldn’t have. Low glucose caused me to sweat profusely, and my brain swam in a blurry sea. This was not the first impression I wanted to make.

I asked for juice, and my friend gave me a glass of something that tasted better than the cheap stuff I purchased for times of need.

“It’s from Whole Foods,” he said.

My friend talked about bands and records, but my words weren’t there. I searched my brain, dug deep, and then deeper, but I was blank, mostly mute beyond “cool” and “yeah.”

The orange juice caused my blood sugars to increase from fifty-nine (and declining) at ten p.m. to a steady one hundred and seventy-three at ten-thirty-one. If I could charge admission for this roller coaster, I’d never have to work again. The next day I thanked him for his hospitality and apologized for being spacey. His response was kind, and his compassion made me want to hear his deejay set even more, which is why I was on the elliptical. That morning I woke with a stomachache, the kind I thought I could cure with sixty minutes of exercise.

Diabetic gastroparesis had other plans.

By the time the machine had reached the fifty-minute mark, I knew something was wrong. I pushed through the final ten minutes, but with three minutes remaining, I could hardly stand. Still, I completed my goal because it’s better to say I exercised for an hour than to say I exercised for fifty-seven minutes.

I raced to my bed, removed my shoes, sweatband, hair tie, and toe socks, and curled into the fetal position. I also placed my Invisalign retainers into a cup.

My Fitbit Charge 5 said it was just after two p.m. There was time for one ondansetron, a shower, and to go to the deejay set.

At four p.m., I lifted my body out of bed, the nausea diminishing, and told myself I could get to Lakewood if I didn’t shower. No problem, I thought. My sheets absorbed the sweat, and I’ll add an extra spray of cologne.

Walking twenty steps to the bathroom was difficult. I sat to pee, hunched in pain and drowsiness. I can do this, I told myself. Get up, put on clothes, and drive.

Two minutes later, I was back in bed.

I texted my friend to explain what had happened after a message approximately one hour earlier told him I was planning to attend. Naturally, I assumed he thought I was flaking. We had recently met, and he could have assumed I was lying; that poor little ol’ Ryan had a tummy ache and couldn’t leave his room.

Thankfully, he said he understood, but I assume people think I am lying when I cancel due to my health. This fear is one of the side effects doctors don’t tell patients about invisible illnesses. I’m forty-four and weigh one hundred and forty-five pounds. A lack of marriages and children means I have my hair — it’s shoulder-length — and it’s mostly brown with an amount of gray that makes me look experienced but not old.

In other words, I don’t look sick.

Tell that to my non-operating pancreas, my vision, and both shoulders on which I have had adhesive capsulitis, diabetic gastroparesis, and an as-yet undiagnosed nerve issue that causes my body to itch all over like a game of Whack-a-Mole whenever I sweat.

Perhaps I don’t look sick, but I am. There are times when I can’t make the deejay set, the barbecue, or the day trip to Ojai. My health means my RSVP is always a maybe, even when I say yes. I quite like the blues when I’m listening to KKJZ on weekends, but not when I have to cancel on friends because my body is not well.

My health is frustrating.

I am tired of being penciled in.

I am tired of doing the right thing and having my body react negatively. I eat one meal a day and exercise regularly, and one week before the stomach pain, I registered for my first marathon. Nine days prior to the flair-up, I ran 21.16 miles.

I invented a saying: You don’t know what it means to have something until you have something. This mantra is why I worry about what my friends think about me. Had I heard of diabetic gastroparesis before I was diagnosed with it? No. Did I understand what it meant to have type 1 diabetes before my diagnosis? Not really. My paternal grandfather had it, but he died the summer between the fifth and sixth grades.

Not knowing is why I don’t think my friends believe me. Not knowing is why I think they think I can be a flake. A visible ailment would be better, my irrational mind thinks, something at which people could point and say, “Oh, yeah, well, that. Of course, he can’t make it.”

I feel compelled to explain and apologize whenever I am unable to be somewhere or do something because of an ailment people can’t see, but I most certainly can feel.

My friends, bless them, don’t seem to mind when I have to cancel. Worry and frustration exist only in my head. This part of diabetes is taking longer to combat than counting carbs and proper insulin intake.

Am I lucky to have type 1 diabetes? Probably not. I am, however, lucky to be surrounded and supported by people who understand.

For them, I am grateful. To them, I say thank you.

Ryan Ritchie is a writer.