My point was two fold. First, everything is interconnected. Second, 10 people with the same diagnosis may have 10 different root causes. This is true for any given chronic dis-ease. Treating symptoms and separate "body parts" is why conventional medicine is ineffective for chronic disease. I've written some of my own personal story here.

For those of you who are already thinking of training for Spring time marathons, and are feeling fatigued, here's my unsolicited advice to you. In addition to a coach or personal trainer, consider this. Hypothyroidism (low energy), adrenal fatigue (stressed out adrenals), low muscle mass (catabolism) and infertility are rampant. Similarly, the root causes may be different for each of us. A functional medicine approach will uncover the hidden internal and/or external stressors, so the body can heal from within. Here's a few common stressors:

1. Food Sensitivities and the SAD standard American diet.
2. Mental/Emotional Stress
3. Gut dysbiosis (bacterial overgrowth)
4. Micronutrient insufficiencies 
1. Zinc and B12 deficiencies are very common especially in vegetarians and vegan diets.
2. Magnesium deficiency is the most common overall. Common symptoms may include insomnia, constipation, tight muscles and hypertension.
3. Vitamin D is a hormone important for immune function and positive gene expression
5. Malabsorption and/ or maldigestion leading to malnutrition. Not having enough stomach acid or pancreatic enzymes due to stress, aging and/or eating on the run is one example.