Medical is required for everyone in the family.
except that the kids (not sure upto which age) may be exempted from xray/ blood test -where they keep poking ur arms in search of vien as if this is the first time they are doing the procedure... :(... i got poked and twisted twice when the needle was inside.. :(

unless you get positive results in the blood test and xrays, visa will not be extended. so have a clear 10 day (min) gap before the visa renewal... just in case the tests have to be repeated (Happened to one of my friend - he had to do the xray twice)

All the best.