15 year old male with years of unexplained fatigue, brain fog, and delayed puberty signs. Looking for possible causes or what should be investigated next.
Hi! I'm a 15 year old male from the Philippines. I've been experiencing persistent low energy and brain fog since around Grade 5, and it's still affecting me now in Grade 11. The symptoms are present almost every day and have significantly affected school, sports, and social life.
Main symptoms
\- Chronic fatigue / very low energy almost every day
\- Brain fog (slow thinking, poor concentration, reduced mental stamina, difficulty finding words)
\- Wake up tired even after 7.5–8 hours of good-quality sleep
\- Exercise intolerance (get tired much faster than friends)
\- Low physical strength
\- Social activities also drain my energy
\- Dark circles under my eyes that don't improve much even with enough sleep
\- Cold hands and feet sometimes
\- Occasional mild lightheadedness when standing (used to be much worse before)
Puberty concerns
\- 15 years old
\- No armpit hair yet
\- Very little body hair
\- Often mistaken for someone much younger than my age
\- Baby face / younger appearance compared to classmates
Things that DON'T seem to explain it
\- Food doesn't noticeably improve the fatigue.
\- Water doesn't noticeably improve it.
\- Coffee only helps a little, if at all.
\- Lying down or resting usually doesn't restore my energy.
\- Sleep is usually deep and uninterrupted.
Recent laboratory results
\- CBC: Normal (Hemoglobin 15.2 g/dL)
\- Iron studies: Normal
\- Ferritin: 648 (possibly elevated from previous iron supplementation and/or recent illness)
\- Vitamin B12: 738
\- TSH: 4.09 (upper end of normal/borderline high)
\- Free T4: Normal
Other information
\- Previously had low blood pressure.
\- I have POIS (Post-Orgasmic Illness Syndrome), but my baseline fatigue continues even after reducing ejaculation, so it doesn't seem to fully explain everything.
\- My pediatrician referred me to a hematologist, but I'm wondering if an endocrine problem should also be investigated.
My questions
Based on this history, what conditions would be highest on your differential diagnosis?
Would delayed puberty or hypogonadism be a reasonable possibility?
Should I be evaluated by a pediatric endocrinologist?
What additional blood tests or imaging would you recommend?
Thank you for taking the time to read this. Any advice or ideas would be greatly appreciated.