Hi! This is my first time posting on Inspire. I currently don't have any diagnosis. I hope I can ask my questions here.

I'm a 30-year-old woman dealing with chronic fatigue, muscle weakness, and frequent hunger, which started at 17 and have gradually worsened despite a healthy lifestyle: I eat a balanced, protein-rich diet, exercise regularly (cycling, aquajogging, walking), have a BMI of ~21, sleep well, and drink about 3L of fluid daily.

Main symptoms:

Chronic fatigue, needing at least 10 hours of sleep at night, then one (to two) more naps to get through the day.
Extremely low muscle endurance, especially in my core — no atrophy, but I can't maintain upright postures (standing, showering, cooking) for more than a few minutes. It feels like my muscles have no stamina. My physio tested this and isometric postures that healthy people could do for more than a minute, I could barely do for 10 seconds.
Activities like cycling are easier, but anything needing core stability leads to pain, cramping, and overuse of superficial muscles.
My muscles constantly feel like I've overtrained.
Physiotherapy and training haven’t helped.
Symptoms worsen significantly when I’m hungry. I need frequent, protein-heavy meals or I feel weak, shaky, and sore, but blood sugar is normal. I often wake at night to eat. The reverse is also true: more muscle strain makes me hungrier.
No neurological symptoms.

Key lab results (tested multiple times):

Carnitine:
- Total: 26–29 µmol/L (normal: 34–78)
- Free: 20–22 µmol/L (normal: 25–54)
- Acylcarnitine + ratio: Normal
Beta-hydroxybutyrate (after 12h fast): Low (42–50 µmol/L) for after a 12 hour fast.
Serum osmolality: Elevated (315–340 mOsm/kg)
Urine (3x): Microhematuria; free hemoglobin 15–25 (normal <10)
Urine organic acids:
- Succinic acid: 8.69 (normal <2.1)
- Lactate/pyruvate ratio: 2.0 (normal <1.4)
- Alpha-ketoglutaric acid: mildly elevated
Amino acids: Low arginine and asparagine
Resting heart rate: 95–100 bpm
Standard labs (thyroid, glucose, insulin, cortisol, electrolytes, vitamins, kidney/liver, CK, etc.): Normal

Because these symptoms are 'vague', only basic testing has been done so far by doctors. These recent labs I ordered independently at a (government-approved) lab, and are the first abnormal findings I’ve had in over a decade, except for the microhematuria. Because of the low carnitine, low BHB, and high succinate acid, I was interested if this could be mitochondrial. I’d like to go to a doctor with a clearer sense of whether these results could be meaningful and give valuable insights. I'm not looking for a specific mitochondrial disease diagnosis, but any insight if there could be (secundary) mitochondrial dysfunction would be very valuable.

Some things I'm interesting in:

Could this combination of symptoms and labs point to metabolic issue and/or mitochondrial issue, even if the carnitine deficiency is only moderate? Are the other lab results off enough to suggest anything pathological?
Would this justify further official testing, such as metabolic or mitochondrial work-up?
Could carnitine still be a meaningful puzzle piece, even if it's not the root cause?
And if this doesn’t sound mitochondrial at all, I’d really appreciate that perspective too.

Thank you for your time!

Mitochondrial Disease

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