There is a hard covering at the end of the toe or finger i.e. fingernail or toenail. If there is a change in nail then it will damage the base of nail or there might be some sort of disease which you don't know. You should consult doctor if this disease still exist.
If there is a change in nail then it might be due to some disease or injury. If there are white spots on the nails then it might be due to liver disease.
The air bubbles under the nails cause the white spots. There are some minor injuries at the base of nail which may happen due to leukonychia. These lines may happen due to several white dots or streaks.
Lack of Protein
If the horizontal band extend up to the nail bed then it may happen due to protein deficiency.
Fungal Superficial Onychomycosis
Warts, fungus, psoriasis, and eczema affect the nails and the white spot may appear. These white spots or streaks which appear on toenail may happen due to fungi.