B737 Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 211; Flight Crew Total 5651; Flight Crew Type 5651
Physiological - Other; Situational Awareness; Confusion; Fatigue
Inflight Event / Encounter Other / Unknown
Company Policy; Human Factors
This pairing and the fatigue it caused started with a day-over in ZZZ1. I only slept at best 4 hours during the day which is actually better than usual for me. It's difficult to wind down enough to sleep when your body is not ready to sleep. The added pressure and stress of knowing what lies ahead later that night and the importance of trying to get some sleep adds to the difficulty in falling asleep. We flew the red eye ZZZ1-ZZZ2. I didn't feel 100% for the flight but not fatigued by definition. Landing in ZZZ2 I went to the hotel and tried not to sleep due to an early show the next morning and if I slept I likely wouldn't sleep well that night. I was too tired however and slept for about 2 hours. I got up and felt like I'd been run over by a truck - just exhausted. That night I went to bed after dinner and got decent sleep of about 8 hours. But it wasn't enough; my alarm went off at XA50 a.m. and it was very difficult to wake up. We flew to ZZZ and coped ok with it but my thought was to consider a fatigue call in ZZZ in-lieu of flying ZZZ-ZZZ3 after a 2 hour sit as scheduled. But I decided to press on instead and we agreed if the flight to ZZZ3 was delayed there would be no way we'd fly it. The 2 hour sit was really tough; more like 3 since we arrived so early. By the time we got on the plane to ZZZ3; I was fighting some drowsiness and lack of focus. We had some coffee and that helped a little. In the air; it was just difficult to keep my eyes open; I definitely missed what ATC said to us a few times which is not typical for me. The flight was otherwise uneventful but looking back I should have called in fatigued for the ZZZ3 leg.
B737 First Officer reported severe fatigue due to flight scheduling.