If you have sickle cell trait (SCT), most days look like everyone else's. But when you fly to a mountain town, hike a 14er, or train at altitude for the first time, your body experiences a real physical change — less oxygen in the air — and on rare occasions, that change can stress an organ you don't think about often: your spleen.
A quick refresher on the spleen. Your spleen sits in the upper left part of your abdomen, tucked behind the rib cage. It does three jobs: it makes immune cells that fight infection, it filters out worn-out red blood cells, and it stores blood. When the spleen loses blood flow, parts of it can die — that's called a splenic infarct.
SCT and splenic infarct. Splenic infarct is rare in the general population. It's still rare in people with SCT — but slightly more likely than in people without the trait, especially under three conditions: 1. High altitude — typically above 1,100 meters (around 3,600 feet, which includes Flagstaff, Denver, Albuquerque, Salt Lake City, and most ski areas). 2. Severe dehydration. 3. Very intense physical activity — especially before your body has acclimatized.
The warning signs:
- Sudden, persistent pain in the upper-left abdomen (sometimes radiating to the left shoulder)
- Chest pain when you breathe in
- Nausea
- Fever
If you experience these — especially at altitude — get medical attention. Tell the team you have SCT. If you're at high elevation and stable enough, ask about transport to a lower altitude.
Can I still fly? Can I still hike Sedona, Flagstaff, the Grand Canyon? Yes. Modern commercial airplanes are pressurized — flying is safe. Spending time and exercising at altitude is also safe with the right precautions:
- Hydrate aggressively — start the day before, continue throughout.
- Pace yourself. The first 24–48 hours at altitude is not the time for a personal best.
- Acclimatize. Spend a couple of low-effort days at altitude before strenuous activity.
- Don't ignore symptoms. Headache, dizziness, persistent abdominal pain — pause, rest, hydrate. Seek care if it doesn't pass.
For Arizona families especially: the elevation gain between Phoenix (1,100 ft) and Flagstaff (7,000 ft) is real. Plan for it. Pack water. Slow your first day.
You're not fragile. You're informed. There's a difference.
— Dr. Rob
📄 Resource: CDC Sickle Cell Trait and Damage to the Spleen: Get the Facts!