This is the 1892nd most frequent Turkish word.
hastalıkların
"Of the diseases" or "of illnesses".
The word "hastalıkların" is in the genitive case, indicating possession or association with 'diseases' in the context of 'their treatment'.
Hastalıkların tedavisinde yeni yöntemler geliştiriliyor.
New methods are being developed in the treatment of diseases.
Here, "hastalıkların" is again in the genitive case, showing the relationship between 'diseases' and 'symptoms'.
Hastalıkların belirtilerini dikkatle incelemek gerekiyor.
It's necessary to carefully examine the symptoms of the diseases.
In this instance, "hastalıkların" specifies possession, showing that the 'increase' belongs to 'diseases'.