Severe swelling of the ankles

My mother is 62 years old. According to her, about forty years old she has swollen ankles in the heat. The reason was never revealed. It was the same with her mother.

The last year the legs are almost all swollen. Even the skin is cracking:

I just made a doplerogram of my legs. She showed full patency of the vessels.

Last summer, in this terrible heat swelling for some reason was not.

In general, he sometimes falls down for an unknown reason.

Legs do not hurt, only fatigue.

Mom can not put any shoes on these "kultyshki."

Advise, please, to which specialist to apply. Or maybe some research needs to be done.

In advance thanks for the answer.

Yours faithfully,
Marina