Keratin, a protein, is a major component of nails. A diet low in protein can lead to weak nail structure and increased breakage. To increase your protein intake, include more lean meats, poultry, fish, legumes, and dairy products in your meals.
2. Hydration Issues
Dehydration can have a significant impact on your nails, making them brittle and more likely to split. Drinking plenty of water throughout the day helps keep nails supple and strong.

3. Environmental Factors
Chemical Exposure
Regular contact with harsh chemicals, including cleaning products, nail polish removers, and detergents, can weaken your nails over time. Wearing gloves while cleaning and choosing non-acetone nail polish removers can help mitigate these effects.
Weather
Exposure to extremely cold or dry conditions can strip moisture from your nails, making them brittle. Using moisturizer and wearing gloves during colder months can provide protection.
4. Health Conditions
Thyroid Diseases
Both hyperthyroidism and hypothyroidism can cause brittle nails. If you suspect your thyroid may be the cause, a simple blood test can help diagnose these conditions and appropriate treatment can be given.
Psoriasis
This skin condition can spread to the nails, causing pitting, abnormal nail growth, and cracking. Treating the underlying psoriasis can often improve nail health.