Bump on Back of Head: Causes & When to See a Doctor

Gerald L. Andriole Jr., MD is going to walk you through some of the causes of a bump on back of head and highlight circumstances when to see a doctor.

There are a lot of things that can trigger the formation of a painful bump on the back of the head. Some of the common causes are bone spurs, injuries, inflamed hair follicle, cysts, and fatty growths.

You can either develop a soft or hard bump on the back of the head. The sizes of the crack vary depending on the cause. Some causes are quite severe, and you will be expected to visit a doctor for treatment.

In this article, we explore some of the possible causes and treatment options available. Also, we highlight situations that may need a doctor’s immediate attention.

What Can Cause a Bump on Back of the Head?

There are plenty of factors that facilitate the development of a bump on the back of your head. However, most of the lumps are harmless.

Sometimes, a lump on the back of the head can result in a severe problem, but this is usually in a rare case.

It is advisable to seek immediate medical help from a professional and reputable doctor when you notice some changes or bleeding on the bump.

Here are some of the possible causes of a bump on the back of the head that hurts:

Ingrown Hair

Ingrown hairs are common after shaving. The shaved hair grows back into the skin rather than outwards. It results in the formation of a pimple-like a bump on the back of the head.

Sometimes, the ingrown hair becomes infected and cause the formation of a pus-filled bump on your head.

However, ingrown hairs are harmless, and they can easily be prevented. Once the hair grows out, the bump on your head will disappear.


This is a condition that results in the development of a bone on top of an already existing one. It is also known as a bone spur, which is common around the joints.

The condition can occur anywhere on the body inclusive of the neck and back of your head. Bony growth is a rare occurrence.

You will need to undergo an X-ray to determine if the sizeable hard bump on the back of the head is as a result of exostosis.

The treatment of the bony growth depends on the complication but an individual need to undergo surgery for correction.

Skull Base Tumors

Although on a rare case, a hard lump on the back on the head can be a tumor. Chordoma is one of the common skull tumors that tend to affect individuals.

It usually grows from the base of the skull at the back of your head. Chordomas have the capability of spreading to other parts of the body.

Visit of doctor to examine the lump before commencing any treatment. A benign will be removed surgically, but a cancerous tumor will need an autopsy.

Head Injury

Head injuries are among the top common cause of bumps on the back of the head. If you fall backward or an object hit your head, then a bump form is an indication that your head was hurt and the body is undergoing a healing process.

Some head injuries might result in a blood clot or scalp hematoma. The formation of lump on the back of your head implies that it is bleeding under the skin. The piece disappears after some few days.

Minor head injuries can be treated at home using over the counter painkillers and cold compress pack.

Severe injuries may require doctor intervention since they tend to cause a concussion. The condition is quite dangerous in case the person does not get proper treatment.

Scalp Folliculitis

This is a skin condition caused by an infection. It makes the hair follicles to become inflamed. The inflammation results in a pimple-like bump on the back of the head filled with pus. However, the crack tends to grow larger.

An individual with razor bumps also tends to experience itching and scalp soreness. If the condition remains untreated, then it could result in open sores on the back of the head.

Treatment of head folliculitis is simple and easy. You will be expected not to wear a hat, stop shaving and avoiding swimming in pools.

Also, use prescription of antibiotics creams, pills, and shampoos. This will help to get rid of these breakouts on the back of the scalp. 

Pilar Cyst

This is a skin cyst that commonly occurs on the scalp and also around the neck. It is also known as trichilemmal cysts.

The scalp cysts are usually marked by being smooth and a dense lump filled with keratin material. It grows gradually, but the diameter sizes tend to vary a lot. These lumps are quite common in women than in men.

The lump on the back of your head is harmless and asymptomatic though it can also result in a painful bump on the back of the head.

Seek medical help from your doctor due to the discomfort and other issues associated with the scalp cyst for removal.


This is a fatty growth that usually occurs underneath the skin. The fatty growths are known to occur anywhere on the body, including the back of the head and neck.

These lumps tend to be painless though the size keeps on changing. Lipomas are a large smooth bump on the back of the head.

The exact cause of these fatty growths is still unknown, and they are quite common in female than male at the age of 40-60 years.

These growths are harmless, and they do not need any form of treatment. It may require surgical removal in case the size increases or causes discomfort. The surgical operation should be done by a professional doctor.

Epidermal Cyst

This is a small hard bump on the back of the head, and they tend to grow underneath the skin. The type of skin cyst tends to be standard on the face and scalp.

It results in a painless lump on head and skin-colored or yellow. The dense mass of the bump is due to the buildup of keratin content.

The cyst tends to go away on their own without treatment. However, in case of infection, they are surgically removed by a doctor.

Seborrheic Keratosis

These are non-cancerous skin growth, and they are quite common among older people. They tend to occur around the neck and back of the scalp.

The lumps are harmless though they tend to have some close similarities with skin cancer. They do not need any treatment.

In case they are suspected to result in skin cancer, then the doctor will remove the sore bump on back of the head using Cryosurgery or any other method.

When to See a Doctor

Seek immediate medical help if the lump on head increases in size causes extreme pain, produces pus, and changes the color.

In case of mechanical impact on the back of the head that result in dizziness, persistent vomiting, bloody discharge and loss of balance, seek immediate medical attention.


Most of the bumps on the back of the head are harmless. However, they are caused by numerous factors, and their treatment depends on the cause.

Consult your doctor in case you are not sure about the cause of the lump on the head for further examination. Seek medical intervention if you notice some weird changes on the chunk.

Sources and References

  1. John Atkinson, M.D. “Bump on the head.” Mayo Clinic
  2. S.J. Chang et al. “Proliferating Trichilemmal Cysts of the Scalp on CT.” American Journal of Neuroradiology
  3. Dr. Liji Thomas. “Exostosis / Osteoma.” Medical News.