A single horizontal groove may affect one nail after local trauma.
Multiple grooves across several nails may suggest a systemic event or a treatment that affected nail growth.
Should Beau's Lines Cause Concern?
A single groove after an obvious injury is often harmless.
However, multiple deep grooves affecting several nails, especially after a serious illness or alongside other symptoms, should be discussed with a healthcare professional.
10. Vertical Ridges: A Common Feature of Aging
Vertical ridges run from the base of the nail toward the tip.
They are also called longitudinal ridges.
In many people, they become more noticeable with age.
The nail surface may appear slightly uneven, but the overall nail structure remains healthy.
These ridges are usually harmless.
Why Do Vertical Ridges Develop?
Nail growth naturally changes over time.
Age-related changes in the nail matrix and surrounding tissues can produce a less uniform nail surface.
Dryness and repeated exposure to water or chemicals may also make ridges more visible.
Some people naturally have more prominent ridges than others.
Are Vertical Ridges a Sign of Vitamin Deficiency?
Not necessarily.
Vertical ridges alone do not reliably indicate a deficiency of magnesium, vitamin B12, or another specific nutrient.
Nutritional deficiencies may affect nails in different ways, but they usually need to be evaluated using the person's diet, medical history, and appropriate laboratory testing.
If vertical ridges are accompanied by severe splitting, unusual discoloration, or other symptoms, seek medical advice.
11. Nail Pitting: A Possible Sign of Psoriasis
Nail pitting appears as small dents or depressions scattered across the nail surface.
The dents may be shallow or deep and can affect one or several nails.
One important cause is nail psoriasis.
Psoriasis is a chronic inflammatory condition that can affect the skin and nails.
When psoriasis involves the nail matrix, it may disrupt the formation of the nail plate, producing pits.
Other nail changes associated with psoriasis include:
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Nail separation from the nail bed.
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Thickening beneath the nail.
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Yellowish discoloration.
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Crumbling.
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Irregular nail surfaces.
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Oil-drop-like discoloration.
Can Nail Pitting Occur Without Skin Psoriasis?
Yes.
Some people develop nail psoriasis without obvious skin plaques.
Nail pitting can also occur in alopecia areata and certain other inflammatory conditions.
Therefore, pitting alone does not establish a diagnosis.
Why Does Early Assessment Matter?
Nail psoriasis can cause pain, interfere with daily activities, and affect quality of life.
It may also be associated with psoriatic arthritis, an inflammatory joint condition.
People who have nail pitting alongside swollen joints, morning stiffness, or persistent joint pain should discuss these symptoms with a healthcare professional.
12. Red or Brown Streaks: Understanding Splinter Hemorrhages
Splinter hemorrhages are thin, reddish-brown or dark lines beneath the nail.
They look like tiny splinters running in the direction of nail growth.
They occur when small blood vessels beneath the nail are damaged and bleed.
Common Causes
In many cases, splinter hemorrhages result from minor trauma.
Possible triggers include:
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Bumping a finger.
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Repetitive pressure.
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Nail biting.
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Aggressive manicures.
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Certain sports or physical activities.
They may appear on one nail and gradually move toward the tip as the nail grows.
When Can They Indicate a Medical Problem?
Multiple splinter hemorrhages without a clear injury may sometimes be associated with systemic conditions.
These include:
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Infective endocarditis.
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Certain forms of vasculitis.
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Other inflammatory or vascular disorders.
Infective endocarditis is an infection involving the inner lining of the heart, often affecting the heart valves.
It can cause fever, chills, fatigue, night sweats, shortness of breath, and other symptoms.
However, splinter hemorrhages alone are not enough to diagnose endocarditis.
If unexplained nail streaks occur alongside persistent fever, chills, or significant illness, medical evaluation is important.
13. Nails That Separate From the Nail Bed
Nail separation is medically known as onycholysis.
It occurs when the nail plate lifts away from the tissue underneath it.
The separated area often appears white because air enters the space between the nail plate and nail bed.
Depending on the cause, the area may also appear yellow, green, or discolored.
Common Causes
Onycholysis can develop due to:
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Repeated trauma.
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Excessive nail cleaning.
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Long or artificial nails.
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Fungal infection.
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Psoriasis.
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Certain medications.
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Thyroid disorders.
Repeatedly placing objects beneath the nail to clean it can worsen the separation.
Once the nail has lifted, the space underneath may collect moisture and debris, increasing the possibility of secondary infection.
When Should You Seek Medical Advice?
A small area of separation after an obvious injury may improve as the nail grows.
However, persistent separation, pain, discoloration, or involvement of several nails deserves assessment.
Treatment depends on the underlying cause.
Keeping the nail short and dry and avoiding further trauma can help prevent worsening.
14. Green Nails: A Possible Sign of Bacterial Colonization
A greenish nail discoloration may be associated with a bacterium called Pseudomonas aeruginosa.
This condition is sometimes called green nail syndrome.
It can develop when moisture becomes trapped between the nail plate and nail bed, particularly when the nail has already separated.
The bacteria produce pigments that can create a green, blue-green, or greenish-black appearance.
Risk factors include:
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Frequent exposure to water.
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Onycholysis.
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Artificial nails.
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Nail trauma.
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Chronic irritation around the nail.
Green discoloration should not automatically be treated as a fungal infection.
A healthcare professional may examine the nail and recommend appropriate treatment.
Keeping the affected area clean and dry and avoiding further nail damage are useful preventive measures.
15. Dark or Red Nails After Injury: When Is It Just a Bruise?
A nail that becomes dark red, purple, or black after an injury may have developed a subungual hematoma.
This is a collection of blood beneath the nail plate.
It can occur after a finger is trapped in a door, struck by a heavy object, or injured during sports.
Symptoms may include:
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Dark discoloration.
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Throbbing pain.
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Pressure beneath the nail.
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Tenderness when touching the fingertip.
Small hematomas may grow out naturally as the nail advances.
Larger injuries can be very painful and may involve a fracture of the fingertip bone.
When Should You Seek Medical Care?
Medical assessment is appropriate when:
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Pain is severe.
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The injury was significant.
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The nail is split or partially detached.
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The fingertip is deformed.
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There is numbness.
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There is an open wound.
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The dark area does not move outward as the nail grows.
Do not attempt to drill or puncture the nail at home to release trapped blood.
A clinician can determine whether drainage or imaging is necessary.
A dark area that develops without a known injury should also be assessed, particularly if it changes over time.
16. Nail Changes and Nutritional Deficiencies
Healthy nail growth requires adequate nutrition.
The body needs protein, vitamins, minerals, and energy to produce normal nail tissue.
However, it is important not to assume that every nail abnormality is caused by a nutritional deficiency.
Many nail changes have non-nutritional explanations.
Iron
Iron is needed for hemoglobin production and normal oxygen transport.
Iron deficiency may be associated with brittle nails and, in more severe cases, spoon-shaped nails.