What causes weak, splitting nails?

what causes weak splitting nails

Splitting nails are common. Soft, weak nails that split down the middle, on the sides or just peel in layers are unfortunately a problem. About 20% of people suffer from brittle nails, especially women over the age of 50. Brittle and splitting nails can be painful, fragile and they catch on things. They are also embarrassing because fingernails are affected most and everyone can see them. 

I recently answered a question about splitting, soft fingernails from a reader of one of the popular web sites where I contribute as a dermatologist and skin care expert.  The question was so good - and so common - that I wanted to include my answer here.

The reader asked why she might have soft, splitting nails and what she could do to try to improve the health and strength of her nails.

Here's my answer to her:

What causes soft, splitting fingernails? 

  • Hereditary nail syndromes that cause nails to be deformed.
  • Age causes nails to become dry, ridged and split over time.
  • Thyroid problems commonly affect nails.
  • Skin conditions such as psoriasis, lichen planus, atopic eczema and alopecia aerate can cause nail fragility including splitting.
  • Rheumatoid arthritis will cause nails to thin and split.
  • Internal conditions such as circulatory diseases, neurologic diseases and chronic anemia can compromise necessary blood supply needs of strong nails and cause fragility. 
  • Systemic medicines such as some chemotherapy drugs, retinoids and antiretroviral medicines are associated with fragile and splitting nails. 
  • Harsh nail care products damage nail structure leading to splitting. 
  • Nail fungal infections can cause nail splitting.
  • Severe nutritional deficiencies can result in nail fragility.

The list of conditions that can impact the strength of your nails is long and complex. It's probably best to see a dermatologist, or at least your primary care doctor to be certain your nail changes are not the 'tip of the iceberg' for some other health issue such as a thyroid problem. If there isn't a health-related cause for your nail changes then the most effective, and almost miraculous way to improve nails is with good old-fashioned nail care that hydrates your nails and replaces and protects lipids. I will give you good guidance below. First, I want to help you understand the structural issues that lead to fragile nails and splitting. 

Common types of nail splitting

Nail splitting along linear ridges

Splitting in linear ridges that run straight down the length of the nail from cuticle to the end of your nail is called onychorrhexis. It is common in women as we age. The splits can crack at the end of your nail and get caught on things. You can have just a small area of your nail effected or up to 70% of your nail may have linear ridges that are fragile and split. This happens because nails grow from cuticle to the edge of your nail in tracks that are like grooves. It can happen for a variety of reasons.

Nail splitting in plates at the end of your nail

Your nail can split at the end in plates. This happens because nails are sort of like phyllo dough with layers of keratin held together with lipid. People most prone to this are those that do a lot of housework and hand washing, both of which causes lipid loss and protein damage. It is called lamellar onychoschizia.

Nail splitting that is flakey white to the top nail surface

This happens from nail polish that damages keratin to cause white flakes on your nail surface. It often also yellows the nails. Repeated layers of polish and older polish formulations make this more likely to happen, though it is hard to avoid if you like to polish your nails. It is called superficial granulation of nail keratin and it is important not to confuse it with a fungal nail infection, which can look similar. 

What are the best ways to strengthen soft and splitting finger nails?

The simple, regular application of the lanolin-rich ointment Bag Balm works wonders to help stop nail splitting. In my almost 30 years practicing dermatology, I've never found a better nail product for this type of nail problem.  For Bag Balm to work it's magic, it's always important to apply it to nails that just had a nice soak in water (i.e. after washing your hands, bathing, doing the dishes, washing the dog or car etc.). I like to apply it to my nails and hands at night and cover them with cotton gloves.

best care for splitting and dry nails

Nail fragility can be helped even more by moisturizing the nail numerous times a day after washing. It also helps to avoid harsh soaps and solvent exposure that cause lipid loss and protein damage in the nail plate. This includes using only a gentle hand soap instead of dishwashing soap or harsh hand soaps.

Dry nails and hand skin are such a common problems (for me too) that I created my Dry Skin Hand Repair Kit with everything we need to avoid dry hands - AND NAILS - and to replenish lost lipids. This is what I use for my 62-year-old nails that naturally want to be fragile, dry and split. It takes work to keep them nice and this is how I do it.

Are there vitamins that will strengthen soft fingernails?

People often also ask me for a vitamin recommendation for their nail problems.  Scientific studies on the benefits of vitamin supplements on nail structure are small and controversial but there are some options that seem sound. Of course, you should always eat a balanced and healthy diet so that you're fortifying your nails with the vitamins and minerals they need from the inside out. 

A biotin (also known as vitamin B7) supplement may also be helpful for splitting nails. 

Biotin is present in foods, especially some grains, walnuts, peanuts, milk, and egg yolks. Your intestinal bacteria (micorbiome) also make it, which is a plug for taking probiotics and eating a healthy diet. (More on this in my free Healthy Eating Guide eBook).

A biotin supplement dosage of 5–10 mg a day is usually recommended. Supplement quality varies and I usually recommend asking the supplement expert in your local health food store for a hair and nail vitamin/mineral formula that contains biotin. This is because other trace minerals and amino acids MAY be useful, but the results depend on the combination of ingredients. (As a caution, I need to mention that biotin supplements can interfere with some lab tests your doctor may order so you need to tell you doctor about all supplements and vitamins if you are to have lab tests done.)

Nails grow slowly so you need to give your nails about a year before you decide if moisturizing and your choice of biotin supplement is truly having an impact on your nail health. 

best care for splitting and dry nailsClick here to see my dermatologist's Dry Hand Skin (and nail) Repair Kit which includes:

  • Bag Balm for your nails.  It's also great for a nightly therapeutic/hydrating moisture drench to heal hand skin or just to keep it healthy,
  • a really great non-greasy hand cream to use throughout the day,
  • the right foaming and non-drying hand soap,
  • the best cotton gloves to cover your Bag Balm when you do that nighttime hydrating treatment, and 
  • a small fingertip file for rough or fissured fingertips.