Primary focal hyperhidrosis does not cause illness. Basically, you just sweat excessively. Although it is a medical condition, it's not a sign of disease or a drug interaction. People who have it are otherwise healthy. The symptoms of primary focal hyperhidrosis are fairly specific.
Potassium iodide is a component in the electrolyte of dye sensitized solar cells (DSSC) along with iodine. Potassium iodine finds its most important applications in organic synthesis mainly in the preparation of aryl iodides in the Sandmeyer reaction, starting from aryl amines.
To balance the charges, we require two nitrate ions per lead (II) ion, and so lead (II) nitrate is #Pb(NO_3)_2#. The potassium ion is #K^+# and the iodide ion is #I^-#. The two charges balance in a #1 : 1# ratio, so potassium iodide is simply #KI#. In lead (II) iodide, the charges balance in a #1 : 2# ratio, so the formula is #PbI_2#. Finally, in potassium nitrate, the charges balance in another #1 : 1# ratio, giving a formula of #KNO_3#. The symbol equation is as follows: