My first chemo experience was terrible. Not because the chemo was unexpected—I knew what I was getting into—but because I had no data. No tracking. No baseline. When symptoms hit, I didn't know if they were normal, emergent, or just noise. I was flying blind.
This time around, I decided to do it differently. Build a system. Use AI to help manage it. Not to cure anything, but to give me visibility into what's actually happening.
Why Track at All?
The honest answer: control. Chemo takes away control. You show up, they poison you, you go home and hope your body bounces back. Tracking doesn't change that dynamic, but it gives you granular visibility into how you're responding. It lets you make small adjustments. It lets you understand your own body instead of just accepting whatever's happening.
It also creates a feedback loop with your medical team. Instead of saying "I felt terrible," you can say "My HRV dropped by 40 bpm on day 3, nausea peaked at 8/10 on days 4-5, and I couldn't eat solid food for 48 hours." That's data. Doctors respond to data.
The Tools
WHOOP for physiological data. Wrist-worn, continuous tracking. Heart rate variability (HRV), resting heart rate, sleep data, recovery scores. This is objective data coming straight from your body.
ChatGPT with a custom prompt for subjective symptom tracking. Every morning and evening, I ask myself the same five questions: how rough do you feel (1-10), nausea level, sleep quality, breakthrough symptoms, and what interventions did you try. I feed this data directly into ChatGPT, which keeps a running log and helps me spot patterns.
A simple spreadsheet for medications and timing. When did I take what? What were the effects? This becomes crucial when your protocol changes mid-cycle.
The Technical Setup (It's Simpler Than You Think)
You don't need anything fancy. WHOOP costs money, but if you're going through chemo, it's worth it. The wrist strap is barely noticeable during blood draws or port access.
For ChatGPT, I created a custom GPT with specific instructions. I pasted in my chemo protocol, dates, drug names, typical side-effect profiles, and then a simple template for daily check-ins. Every time I log in, I answer the same prompts, and the AI keeps the full history. This matters because it remembers patterns that you'd forget.
The spreadsheet is literally just: Date | Time | Drug/Intervention | Dose | Notes. Nothing complex.
The Emotional Impact
Here's what I didn't expect: having data is emotionally different than flying blind. When you don't know what's normal, every symptom feels catastrophic. "Is this nausea bad? Is it an emergency?" With baseline data, you know. You've seen what day 3 looks like. You've got recovery scores from yesterday. It becomes contextualised.
That contextualisation—even if it doesn't change the medical outcome—changes how you feel. You're not a victim of random symptoms. You're someone managing a process. That's a different mental state entirely.
Why This Matters for Your Next Cycle
Chemo will likely come back for me. When it does, I'm not starting from scratch. I know: my nausea peaks on day 3-4, my sleep is most vulnerable days 2-5, my recovery drops predictably, and my HRV is a leading indicator of breakthrough symptoms. That's gold. That means my oncologist and I can be proactive in the next cycle instead of reactive.
I'm not pretending this is a cure. I'm not saying tracking will change my prognosis. But it will change how I experience treatment, and it will make the medical conversations more precise. That matters.
The setup takes maybe two hours. The daily commitment is ten minutes. If you're going through chemo and you want to actually understand what's happening in your body instead of just accepting it, this is a good place to start.