Black lips or having very dark colored lips is contributed by several factors and can be used as indicators for certain conditions that are happening inside the body. Though very rare, there are certain severe medical conditions that can cause the lips to turn a darker shade or even black like having cancer. It can be contributed by living a modern lifestyle, certain eating habits, and some medications. There are patients that naturally have black lips or dark-colored lips.
Substantial - either now or in the next three months. 1  significant harm or danger due to your physical or mental health or behaviour.  being unable to carry out many personal care and daily household chores, causing significant risks to your independence.
Making up your own definition of medical necessity is not appropriate. The standard definition of medical necessity that HHS, all of the states, and with slight modifications to exclude non-FDA stuff, all of the private payors, is the 1999 AMA Definition of Medical Necessity.