Many people with von Willebrand disease don't know it because the signs are mild or absent. The most common sign of the condition is abnormal bleeding.

There are three main types of the disease. The amount of bleeding varies from one person to another, depending on the type and severity of the disease.

If you have von Willebrand disease, you might have:

• Excessive bleeding from an injury or after surgery or dental work
• Frequent nosebleeds that don't stop within 10 minutes
• Heavy or long menstrual bleeding
• Heavy bleeding during labor and delivery
• Blood in your urine or stool
• Easy bruising or lumpy bruises

Menstrual signs and symptoms might include:

• Blood clots greater than 1 inch (2.5 centimeters) in diameter in your menstrual flow
• The need to change your menstrual pad or tampon more than once an hour
• The need to use double sanitary protection for menstrual flow
• Symptoms of anemia, including tiredness, fatigue or shortness of breath

Contact your doctor if you have bleeding that lasts a long time or is hard to stop.

The usual cause of von Willebrand disease is an inherited abnormal gene that controls von Willebrand factor — a protein that plays a key role in blood clotting.

When you have low levels of this protein or it doesn't work as it should, small blood cells called platelets cannot stick together properly nor attach themselves normally to the blood vessel walls when an injury has occurred. This interferes with the clotting process and can sometimes cause uncontrolled bleeding.

Many people with von Willebrand disease also have low levels of factor VIII, another protein that helps in clotting.

Factor VIII is involved in another inherited clotting disorder called hemophilia. But unlike hemophilia, which mainly affects males, von Willebrand disease affects males and females and is usually milder.

Rarely, von Willebrand disease can develop later in life in people who didn't inherit an affected gene from a parent. This is known as acquired von Willebrand syndrome, and it's likely caused by an underlying medical condition.

The main risk factor for von Willebrand disease is having a family history of it. Parents pass the gene for the disease to their children. Rarely, the disease skips generations.

The disease is usually an "autosomal dominant inherited" disorder, which means you need a mutated gene from only one parent to get the disease. If you have the gene for von Willebrand disease, you have a 50% chance of transmitting this gene to your children.

The most severe form of the condition is "autosomal recessive," which means both of your parents have to pass a mutated gene to you.

Rarely, von Willebrand disease can cause uncontrollable bleeding, which can be life-threatening. Other complications of von Willebrand disease can include:

• Anemia. Heavy menstrual bleeding can cause iron deficiency anemia.
• Swelling and pain. This can be a result of abnormal bleeding in the joints or soft tissue.

If you plan to have children and have a family history of von Willebrand disease, consider genetic counseling. If you carry the gene for von Willebrand disease, you can pass it on to your offspring, even if you don't have symptoms.

Mild forms of von Willebrand disease can be difficult to diagnose because bleeding is common, and, for most people, doesn't indicate a disease. However, if your doctor suspects you have a bleeding disorder, he or she might refer you to a blood disorders specialist (hematologist).

To evaluate you for von Willebrand disease, your doctor will likely ask you detailed questions about your medical history and check for bruises or other signs of recent bleeding.

Your doctor will also likely recommend the following blood tests:

• Von Willebrand factor antigen. This determines the level of von Willebrand factor in your blood by measuring a particular protein.
• Von Willebrand factor activity. There are a variety of tests to measure how well the von Willebrand factor works in your clotting process.
• Factor VIII clotting activity. This shows whether you have abnormally low levels and activity of factor VIII.
• Von Willebrand factor multimers. This evaluates the structure of von Willebrand factor in your blood, its protein complexes and how its molecules break down. This information helps identify the type of von Willebrand disease you have.

The results of these tests can fluctuate in the same person over time due to factors such as stress, exercise, infection, pregnancy and medications. So you might need to repeat some tests.

If you have von Willebrand disease, your doctor might suggest that family members undergo tests to determine if this condition runs in your family.

Even though von Willebrand disease has no cure, treatment can help prevent or stop bleeding episodes. Your treatment depends on:

• The type and severity of your condition
• How you've responded to previous therapy
• Your other medications and conditions

Your doctor might suggest one or more of the following treatments to increase your von Willebrand factor, strengthen blood clots or control heavy menstrual bleeding:

• Desmopressin. This medication is available as an injection (DDAVP). It's a synthetic hormone that controls bleeding by stimulating your body to release more of the von Willebrand factor stored in the lining of your blood vessels.

  Many doctors consider DDAVP the first treatment for managing von Willebrand disease. It can be used before minor surgical procedures to help control bleeding. You might be given a trial of desmopressin to make sure it's effective for you.

• Replacement therapies. These include infusions of concentrated blood-clotting factors containing von Willebrand factor and factor VIII. Your doctor might recommend them if DDAVP isn't an option for you or has been ineffective.

  Another replacement therapy approved by the Food and Drug Administration for treating adults 18 and older is a genetically engineered (recombinant) von Willebrand factor product. Because recombinant factor is made without plasma, it can reduce the risk of a viral infection or allergic reaction.

• Oral contraceptives. In addition to preventing pregnancy, these drugs can help control heavy bleeding during menstrual periods. The estrogen hormones in birth control pills can boost von Willebrand factor and factor VIII activity.
• Clot-stabilizing medications. These anti-fibrinolytic medications — such as aminocaproic acid (Amicar) and tranexamic acid (Cyklokapron, Lysteda) — can help stop bleeding by slowing the breakdown of blood clots. Doctors often prescribe these drugs before or after a surgical procedure or tooth extraction.
• Drugs applied to cuts. A fibrin sealant (Tisseel) placed on a cut helps curtail bleeding. This is applied like glue using a syringe. There are also over-the-counter products to stop nosebleeds.

If your condition is mild, your doctor might recommend treatment only when you're having surgery or dental work or when you've had a trauma, such as a car accident.

These self-care tips can help you manage your condition:

• Switch pain relievers. To help prevent bleeding episodes, talk with your doctor before taking blood-thinning medications — such as aspirin, ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve). Your doctor might instead recommend pain and fever relievers such as acetaminophen (Tylenol, others).
• Tell your doctors and dentist. Let your doctors or dentist know that you have von Willebrand disease before you have surgery, start a new medication or give birth. Also mention whether anyone in your family has a history of excessive bleeding.
• Consider wearing a medical ID bracelet. Make sure it notes that you have von Willebrand disease, which will be helpful to medical personnel if you're in an accident or taken to an emergency room. Also carry a medical alert card in your wallet.
• Be active and safe. Exercise is part of attaining or maintaining a healthy weight. Avoid activities that could cause bruising, such as football, wrestling and hockey.

You'll likely see your family doctor if you think you have a bleeding problem. You then might be referred to a doctor who specializes in the diagnosis and treatment of bleeding disorders (hematologist).

Here's some information to help you get ready for your appointment.

What you can do

Ask about pre-appointment restrictions when you make the appointment. You might need to follow dietary restrictions or fast for 8-10 hours if blood tests are scheduled.

Make a list of:

• Signs or symptoms that involve bleeding, including how often, how severe and for how long. Include unusual bruising. Your doctor will want to know if you have a history of nosebleeds or easy bruising since childhood. If you menstruate, are your periods extended and heavy?
• Key personal information, including major stresses or recent changes — both positive and negative.
• Key medical information, including other medical problems and close relatives who bleed easily. Also list medications, vitamins or other supplements you take, including doses.
• Questions to ask your doctor.

Take a family member or friend along, if possible, to help you remember the information you'll be given.

For von Willebrand disease, questions to ask your doctor include:

• What's the most likely reason for my symptoms?
• What treatment do you recommend, and how will you monitor whether it's working?
• What are the possible side effects of the medications you're prescribing?
• Does this condition increase my risk of other medical problems?
• What will I need to do before having surgery or dental procedures?
• Does this condition increase my risk of health problems during pregnancy and childbirth? Are treatment options available to reduce that risk?
• Do I need to avoid certain physical activities or types of exercise?
• I have other health conditions. How can I best manage them together?

What to expect from your doctor

Your doctor might ask:

• Have you had bleeding from a small wound that lasted more than 15 minutes or recurred during the week following the wound?
• Have you had a nosebleed that lasted more than 10 minutes or needed medical attention?
• Have you had unexpected bruising? Have you ever felt a lump under the bruise?
• If you menstruate, how many days do your periods last? How often do you change your tampon or sanitary pad during a period? Have you seen blood clots in your menstrual flow?
• Have you had blood in your stool that wasn't explained by a known medical problem, such as a stomach ulcer or colon polyp?
• Have you ever needed medical attention for bleeding during or after surgery, dental procedures, childbirth or injury?
• Have you had anemia or needed a blood transfusion?

What you can do in the meantime

While you wait for your appointment, avoid pain relievers that can increase your risk of bleeding, such as aspirin, ibuprofen (Advil, Motrin IB, others) and naproxen sodium (Aleve). If you need relief for aches and pains, try acetaminophen (Tylenol, others) instead.

Steer clear of contact sports associated with a high risk of bruising or injury, such as football and hockey. If you have medical or dental procedures scheduled, tell your doctor or dentist about your history of heavy bleeding from minor injuries.

If you're having a procedure that's not urgent, reschedule it until after you've been evaluated for a bleeding disorder.