There's a big difference between the tests from 23andMe and Theranos. 23andMe produces data that's risk-based (i.e. your risk of developing coronary heart disease) but isn't immediately actionable. Most of what you could do to address the risks reported by 23andMe is stuff you should already be doing -- eating healthy, sleeping more, exercising, quitting smoking/alcohol.

Theranos was doing standard lab tests, like blood electrolytes. Blood electrolytes are highly regulated by the body and are only abnormal in serious medical illness. If your blood sodium level is too low (hyponatremia) that's a medical emergency and you need to be in the ER (hyponatremia can indicate end-organ failure like renal failure, heart failure; it can also indicate serious endocrine abnormalities like SIADH or too much water intake 'frat-boy' syndrome). Uncorrected hyponatremia can lead to permanent neurological disease (classically brainstem herniation).