Can you bleed from your bones?

I was talking to my science teacher about the body specifically the red bone marrow.

She said that blood is created in the red bone marrow. Does that mean that if you were to cut a fresh bone open it would bleed?

Yes, bones too bleed if they get damaged (break or bruise). This is because bones are highly vascularised organs and breaking of bones will indeed rupture the blood vessels causing bleeding. Main artery which supplies blood to bone is nutrient artery , others are epiphyseal, metaphyseal and periosteal arteries. Skeletal system receives about 15.6% of cardiac output. Since bones contain very low percentage of water ( about 31% ) comapred to others like skin(64%),brain and heart (73%) and lungs ( 83%). So the saying "as dry as bone " stills holds well.




How do broken bones heal?

A fall, followed by a crack – many people are no stranger to this. Broken bones are painful, but the majority heal very well. The secret lies in stem cells and bone’s natural ability to renew itself.

Share on Pinterest Bone heals by making cartilage to temporarily plug the hole created by the break. This is then replaced by new bone.

Many people think of bones as being solid, rigid, and structural. Bone is, of course, key to keeping our bodies upright, but it is also a highly dynamic and active organ.

Old bone is constantly being replaced by new bone in a finely tuned interplay of the cells present. This mechanism of daily maintenance comes in handy when we are faced with a broken bone.

It allows stem cells to first produce cartilage and then create new bone to heal the break, all of which is facilitated by a finely tuned sequence of events.

Each year, around 15 million fractures, which is the technical term for broken bones, occur in the United States.

The immediate response to a fracture is bleeding from the blood vessels dotted throughout our bones.

The clotted blood collects around the bone fracture. This is called a hematoma, and it contains a meshwork of proteins that provide a temporary plug to fill the gap created by the break.

The immune system now springs into action to orchestrate inflammation, which is an essential part of healing.

Stem cells from the surrounding tissues, bone marrow, and blood respond to the immune system’s call, and they migrate to the fracture. These cells start off two different pathways that allow bone to heal: bone formation and cartilage formation.

New bone starts to form mostly at the edges of the fracture. This happens in much the same way that bone is made during normal, everyday maintenance.

To fill the void space between the broken ends, cells produce soft cartilage. This may sound surprising, but it is very similar to what happens during embryonic development and when children’s bones grow.

Cartilage, or soft callus , formation peaks around 8 days after injury. However, it is not a permanent solution because cartilage is not strong enough to withstand the pressures that bones experience in our daily lives.

The soft callus is replaced first with a hard, bone-like callus . This is pretty strong, but it is still not as strong as bone. Around 3 to 4 weeks after the injury, the formation of new mature bone starts. This can take a long time – several years, in fact, depending on the size and site of the fracture.

However, there are cases wherein bone healing is not successful, and these cause significant health problems.

Fractures that take an abnormally long time to heal, or those that do not join back together at all, occur at a rate of around 10 percent.

However, a study found that the rate of such non-healing fractures was much higher in people who smoke and people who used to smoke. Scientists believe that this may be due to the fact that blood vessel growth in the healing bone is delayed in smokers.

Non-healing fractures are particularly problematic in areas that carry a lot of load, such as the shinbone. An operation to fix the gap that will not heal is often necessary in such cases.

Orthopedic surgeons can use either bone from elsewhere in the body, bone taken from a donor, or man-made materials such as 3-D-printed bone to fill the hole.

But in the majority of cases, bone makes use of its remarkable ability to regenerate. This means that the new bone that fills the fracture closely resembles the bone before the injury, without a trace of a scar.

When to Call the Doctor

Call your doctor if you have any of these symptoms:

  • A lot of bleeding from your mouth or gums
  • A nosebleed that does not stop
  • Bruises on your arms or legs
  • Small red or purple spots on your skin (called petechiae)
  • Brown or red urine
  • Black or tarry looking stools, or stools with red blood in them
  • Blood in your mucus
  • You are throwing up blood or your vomit looks like coffee grounds
  • Long or heavy periods (women)
  • Headaches that do not go away or are very bad
  • Blurry or double vision
  • Abdominal pains


These depend on which type of plasma cell neoplasm you have.

MGUS doesn’t usually cause any symptoms.

Lymphoplasmacytic lymphoma symptoms include:

  • Blurred vision
  • Dizziness
  • Headaches
  • Tiredness
  • Weight loss
  • Shortness of breath
  • Hearing problems
  • Numbness or tingling

Plasmacytoma may cause pain (in bones or soft tissue) and broken bones.

Multiple myeloma may not cause any problems early on. When it does, common signs and symptoms include:

  • Weak or broken bones
  • Feeling very tired
  • Getting sick often
  • Pain in your bones
  • Problems breathing

Interrupted Circulation

Like all of your organs, your intestine must have a constant supply of blood to perform its functions. If the blood supply to your colon is interrupted -- a condition called ischemic colitis -- you may develop severe abdominal pain and rectal bleeding. The pain of ischemic colitis is usually felt along the left side, as this side of your colon is most likely to lose its blood supply. Ischemic colitis most often occurs in older adults. People who smoke or have high cholesterol are at increased risk. Ischemic colitis may necessitate removal of a portion of the colon.

Bone Facts

The smallest bone in the human body is called the stirrup bone, located deep inside the ear. It's only about 3 millimeters long in an adult.

The longest bone in the human is called the femur, or thigh bone. It's the bone in your leg that goes from your hip to your knee. In an average adult, it's about 20 inches long.

Marieb. E.N. (1989) Human Anatomy and Physiology, CA: Benjamin/Cummings Publishing Company, Inc

Heller, H.C., Orians, G.H., Purves, W.K., Sadava, D. (2003) Life: The Science of Biology, 7th Edition. Sunderland, MA: Sinauer Associates, Inc. & W. H. Freeman and Company

Skeleton Image: By Lady of Hats - Mariana Ruiz Villarreal, via Wikimedia Commons.

Management and Treatment

How are brain hemorrhages treated?

Any type of bleeding inside the skull or brain is a medical emergency. If you or a loved one have experienced a blow to the head or have symptoms that may indicate a brain bleed, call 911. It is important to get to a hospital emergency room immediately to determine the cause of the bleeding and to begin medical treatment.

If a stroke has occurred, the cause (bleeding or blood clot) must be determined so that the appropriate treatment can be started. Prompt medical treatment can help limit damage to the brain, which will improve your chance of recovery.

Surgery may be needed in the following situations:

  • Bleeding (hemorrhage) may require immediate decompression of the brain to release pooled blood and relieve pressure. Decompression may be done through a burr hole procedure (drilling a hole in the skull to allow blood drainage), a craniectomy incision (partial removal of the skull to allow the swelling brain to expand), or a craniotomy (opening of the skull cavity).
  • A cerebral aneurysm that has not ruptured may require clipping or filling (“sealing off”) of the aneurysm through a craniotomy surgical procedure, or an angiography-type procedure to prevent a future rupture.
  • An arteriovenous malformation (AVM) that has not ruptured is treated by direct removal of the AVM through surgery, use of computer-guided radiation to close off the abnormal vessels or use of a special glue or other filler to block the blood flow from smaller blood vessels into the AVM or the vessels that supply the AVM.
  • Some brain hemorrhages do not require surgery. The decision depends on the size, cause and location of the bleed and other factors.

Other treatments may include:

  • Anti-anxiety drugs and/or medication to control blood pressure.
  • Anti-epileptic drugs for seizure control.
  • Other medications needed to control other symptoms, such as painkillers for severe headache and stool softeners to prevent constipation and straining during bowel movements.
  • Nutrients and fluids as needed. These may be given through a vein (intravenously), or a feeding tube in the stomach (gastronomy tube), especially if the patient has difficulty swallowing.

What does rehabilitation after a brain bleed entail?

The goals of long-term treatment are to help you regain the functions needed for daily living, as much and as soon as possible, and to prevent future brain hemorrhages. Rehabilitation and recovery time vary according to each person’s unique brain bleed and the extent of rehabilitation possible.

Long-term rehabilitation treatment may include:

  • Physical therapy.
  • Speech therapy or alternative forms of communication.
  • Occupational therapy.
  • Changing lifestyle habits to reduce risk of another hemorrhage. (See next question.)

Significantly more mild bleeding episodes with AstraZeneca vaccine than mRNA vaccines

Credit: Pixabay/CC0 Public Domain

An unpublished preprint of a study done by the Norwegian Institute of Public Health, NIPH, concludes that the AstraZeneca COVID-vaccine may lead to less severe bleeding disorders, and not only the very rare blood clotting side effects that have been widely reported.

The researchers used an ongoing study called the Norwegian Mother, Father and Child Cohort Study to examine questions related to side effects observed in people who have received the AstraZeneca vaccine in various European countries.

Participants were asked through electronic questionnaires about potential side effects after COVID-19 vaccinations such as skin bleeding, nose bleeds and bleedings in the gum (gingival bleeding). This was linked with the type of vaccine they had received.

Signficantly more cases of bleeding

The risk of bleeding was 20 times higher among people vaccinated with a adenovector-vaccine, like AstraZeneca, compared to those who had received an mRNA-vaccine.

Only four out of the nearly 2900 participants who had received an mRNA vaccine, like the ones produced by Moderna and Pfizer, reported skin bleeding as a side effect. This equals 0.1%.

124 of nearly 4500 who had received the AstraZeneca vaccine reported the same—amounting to 2.8%.

The differences were also stark for nose bleeds and gum bleeds:

  • Nose bleeds—Adenovector: 2.0%, mRNA vaccine: 0.3%
  • Gum bleeds—Adenovector vaccine: 1.6%, mRNA vaccine: 0.2%

"In this study, cohort participants vaccinated with the adenorivus-vectored vaccine reported bleeding episodes significantly more frequent as compared to recipients of mRNA vaccines," the researchers write.

The only other variable that showed a clear association to bleeding episodes, besides the different vaccines, was gender. 3.1% of women reported skin bleeding as opposed to 1.3% men.

The study will soon be available as a preprint on Medrxiv, according to the lead author, Lill Trogstad. ScienceNorway has read the preprint.

Self-reported side effects

Trogstad from the division of Infection Control and Environmental Health at the NIPH cautions that this is an observational study. The side effects have not been clinically observed, they are self-reported by those who have answered the digital questionnaire.

"We don't yet know what this means. There is a significant difference in reported side effects based on which vaccine the recipients have been given. It's an interesting finding, but we cannot yet know the mechanisms behind these observations," she says to

"However, one might speculate that the adeno-vectored vaccine may increase risk of minor bleedings," she says.

The researchers discuss the possibility of awareness bias, that participants who received the AstraZeneca vaccine might overreport bleedings due to all the attention this has been given in the media lately. Although this cannot be entirely ruled out, "it is unlikely to explain the large differencs in reported bleeding episodes reported in the current study, they write.

Need to analyze blood samples

Whether or not these less severe bleedings are related to the rare and serious blood clotting events, cannot be determined without further investigation.

"We have not yet analyzed blood samples from these participants, and until we do that we won't know if this is related to the rare side effects otherwise observed related to the vaccine," Trogstad says.

The study will be followed by an analysis of blood samples, she reports.

"We have blood samples from many of these participants from throughout the pandemic, and we just started a new round of collections. So we have samples from before and after the vaccination that we can include," she says.

Most likely caused by adenoviral vector

"This is an important observation, and underscores the connection between the AstraZeneca vaccine and the rare and serious side effects of blood clots that we have seen so far," says Gunnveig Grødeland, senior researcher at the University of Oslo and group leader of the research group Influenza and Adaptive Immunity. She has not been involved with the study.

"Looking at these observations in relation to the cases that are coming out of the U.S. from the Johnson & Johnson vaccine, it is starting to become clear that these side effects most likely are caused by characteristics from the adenoviral vector used to deliver the vaccine," she says.

The AstraZeneca vaccine uses a chimpanzee virus while Johnson & Johnson use a human virus.

"Regardless of whether it is human or from an animal then, it becomes apparent that it is the adenovirus which gives the side effects."

Not a conventional vaccine technology

Grødeland believes this calls for a cautious approach to using adenoviral vectors in vaccines.

"I don't know where it comes from, but somehow there is a misconception out there that this is a well-known tried and tested technology. But that is wrong," she says.

The format is used in the Ebola vaccine, which has been considered a success. But other than that, this is not a conventional method, the researcher explains.

"It has been used experimentally for more than 20 years, there are plenty of studies. But it has not been used in a vaccine which has been rolled out to the masses," Grødeland says.

A late stage clinical trial will typically involve between 10,000–20,000 vaccinated people and a similar number of non-vaccinated people as a control group. The serious blood clotting side effect is very rare, and so it is not odd that they have not occurred in these studies, according to Grødeland.

"In Norway, where we have had a high prevalence, there is about one case per 20,000. So it goes without saying that this is difficult to catch in a clinical study."

The bleedings in the unpublished NIPH-study are mild—nose bleeds and gum bleeds are not so serious.

"A higher prevalence of these kinds of bleedings may be something we have to tolerate. However, what they show us is that there seems to be something about the adenoviral format which is causing this. Which again means that we can assume that we will not see the same effect from the Pfizer or Moderna vaccines—or vaccines based on other formats," Grødeland says.

Gender is not the answer

The fact that more women than men report the side effects is a well-known phenomenon—women tend to form stronger immune responses from vaccines.

"Just because there is an overweight of women who experience these side effects doesn't' mean we can count men out—there are also cases with men experiencing this. So we can't just say that now we give this vaccine to men while women get something else. I'm afraid it's not that simple."

Warnings and Precautions

Early Signs and Symptoms of Throat Cancer

Only about 6 percent of nosebleeds require medical care to stop the bleeding, according to the American Rhinologic Society 1. However, it's important to seek immediate medical attention for a nosebleed that is heavy or will not stop within 10 to 15 minutes when applying firm but gentle pressure.

Additionally, seek medical evaluation as soon as possible if you experience recurring nosebleeds. While cancer is among the less common causes of nosebleeds, it's important not to ignore this potential cancer warning sign.