I had CFS and I believe it is almost always physical. It’s hard to tell because it feels mental. I saw a ton of different Drs and endocrinologists who all told me I was physically fine and it was mental. I looked healthy, I felt depressed. It significantly impacted my life.<p>After many years of self experimentation and internet reading here is what made sense for me. I had high T4, low T3, and low cortisol levels. My working theory is subclinical hypothyroidism and adrenal fatigue. The theory for the cause is long term high levels of stress (tech startup) and imbalanced microbiota.<p>I treat it with natural desiccated thyroid (edit: not compacted thyroid), licorice root, light therapy, blue blockers, strict sleep schedule, quit coffee, regular exercise, paleo diet, probiotics, and fermented food. The thyroid meds made the biggest and most immediate difference, it was like switching a light back on. I’ve quickly turned into a hippy and I’ve never felt better.<p>Thank you internet!