Po-Wei Chen, MD Po-Wei Chen, MD

At the sidelines of track meets, road races, and ball games, the most common accident isn’t a fracture. It’s someone collapsing. And the first question to ask on the scene isn’t “Are they dehydrated?” but “When did they collapse?" The answer to this question splits the situation into two different worlds: collapsing during the race, and collapsing after crossing the finish line. Collapsing during the race: Treat as the worst-case scenario first If a person suddenly falls to the ground while running, playing, or competing, and wasn’t hit by anything, the correct response is to first treat it as cardiac arrest: call for help, call an ambulance, grab an AED, and start CPR. ...

Let’s start with the most counterintuitive thing: when a kid collapses during hot weather exercise and their mental status is off, the right order is to cool them down on site first, then send them to the hospital. Not call an ambulance and figure it out on the way. The international consensus is blunt—cool first, transport second. Because what determines whether they suffer permanent damage isn’t how fast they get to the ER, but how long their body temperature stays above 40°C. ...

Bottom line up front: If your child has a painful bump just below the kneecap, it’s not growing pains. It has a name: Osgood-Schlatter, also known as tibial tubercle apophysitis. And contrary to what many people have heard—it doesn’t “completely go away when you grow up." I’m writing this for parents who have 10- to 15-year-olds currently running and jumping in sports. How to tell if it’s growing pains Growing pains usually happen in both legs, ache in the evening or middle of the night, and have no clear point of tenderness. By the next morning, it’s like nothing happened. ...

Let me say the most important thing first: sarcopenia is not “just what happens when you get old.” It’s a disease that can be detected—and one that actually improves with exercise and diet. This post is written for two kinds of people: you, if an older adult at home has recently started walking slower or can’t open jars; and you, if you’re past fifty and starting to feel your stamina isn’t what it used to be. The second group is actually more important, because the latest 2025 Asian consensus pulled the age to start paying attention forward to fifty. ...

Let’s start with the most important point: If a senior’s shoulder repeatedly swells with fluid, and you can draw out a large bottle every time, it’s mostly not “simple degeneration,” but another disease. This post is for you if you have an older family member whose shoulder repeatedly fills with fluid, has been aspirated several times, but always swells up again quickly. What is this disease? Inside the shoulder is a group of tendons called the “rotator cuff,” which is responsible for hanging the arm steadily in the shoulder socket. As we age, this tendon group can tear completely. After it tears, the humeral head moves upward, and bone rubs directly against bone. The fine calcium salt crystals ground off fall into the joint cavity, which in turn stimulates the joint lining to inflame and continue the destruction. ...

This is the third post in the getting-started-with-AI series. Part 1 covered how to set it up, and Part 2 covered how to talk to it and set up guardrails. At the end of Part 2, I said: the hard part is never “how to ask,” it’s “how to design the workflow.” This post will wrap up that statement. The answer might be the opposite of what you think: workflows aren’t designed, they grow. ...

I previously shared building a money-saving dashboard for AI. Back then, I was mostly looking at “how much money I spent.” Using it now, I realized what really hurts isn’t the money, it’s the quota: Claude Code’s subscription has 5-hour and 7-day rolling windows. Hit the limit, and it just stops dead in its tracks. In this post, I’ll share the open-source little tool we made for this: claude-pacer (github.com/drpwchen/claude-pacer). Why build this? It started with getting cut off in the middle of the night a few times. ...

This is an article that I’ll keep updating. ...

The previous post, Getting Started from Scratch, was about how to install it and get it running. This post is about using it well. And that is completely different from just getting it to run. I’ve found that what really determines the outcome isn’t which model you use or whether you can code. It’s how you delegate tasks and how you set up guardrails. The stuff in this post isn’t tied to a specific tool; it applies even if you use ChatGPT (I’ll explain the differences in the last section). ...

Why “too many notes” and “no notes” are the same thing Let me start with a rule I decided on early and haven’t changed since: in my note vault, there can only be one note per topic. It’s not about being a neat freak. It’s because if the same thing is covered in five different places, I have to open five files when I look something up, and figure out which version actually counts. That organization work didn’t disappear, it was just left intact for my future self. And my future self is usually seeing patients in clinic or rushing to finish slides, with no time to do this. The chaos caused by too much information is the exact same pain as not having enough information. ...