There are plenty of indicators that could be monitored in various patients for various diseases, but a lot of them may require doing things that are beyond the

There are plenty of indicators that could be monitored in various patients for various diseases, but a lot of them may require doing things that are beyond the ability of someone who is not medically trained. Some of them require intravenous blood samples, for example. But others are like example you mention (which only requires that the patient weigh themselves at a given time each day). It would be nice if we could make it simpler for people to measure things like their own hemoglobin A1C, blood urea nitrogen/creatinine, blood flow around organs/extremities, etc. and send the data to a service that can be used to alert medical staff if something looks like it's getting worse.