Hi everyone. I'm a 15-year-old male, and I've had persistent fatigue and brain fog since around Grade 5 (elementary school). It's been present almost every day for years and has affected school, sports, and my social life.
Symptoms
Chronic fatigue / low energy
Brain fog (slow thinking, poor concentration, trouble finding words)
Wake up tired despite 7.5–8 hours of good-quality sleep
Exercise intolerance and low physical strength
Socializing drains me quickly
Dark circles under my eyes
Cold hands and feet sometimes
Occasional mild lightheadedness when standing
Other things that concern me
I'm 15 and still don't have armpit hair, with very little body hair overall.
People often think I'm much younger than my age.
Tests so far
CBC: Normal (Hemoglobin 15.2 g/dL)
Iron studies: Normal
Ferritin: 648
Vitamin B12: 738
TSH: 4.09 (borderline high), Free T4: Normal
My pediatrician has referred me to a hematologist, but I'm wondering if I should also see a pediatric endocrinologist because of the delayed puberty signs.
If you've had similar symptoms, what was eventually found to be the cause? Are there any conditions or tests you think I should discuss with my doctor?
I'm not looking for a diagnosis—just ideas that I can bring up with my healthcare team.