This condition occurs almost exclusively in males born to carrier mothers due to X-linked recessive inheritance.

Superficial bleeding resulting from abrasions or shallow lacerations may persist, with scabs easily breaking due to the deficiency of fibrin, potentially leading to re-bleeding.

However, mild haemophilia A is known to occur in heterozygous females due to X-inactivation, so it is recommended that levels of factor VIII and IX be measured in all known or potential carriers prior to surgery and in the event of clinically significant bleeding.

Individuals with mild haemophilia often experience few or no bleeding episodes except in the case of serious trauma (i.e. tooth extraction, or surgery).

These devices have made prophylaxis in haemophilia much easier for families because the problems of finding a vein for infusion several times a week are eliminated.

[18] These infections can usually be treated with intravenous antibiotics but sometimes the device must be removed,[19] also, there are other studies that show a risk of clots forming at the tip of the catheter, rendering it useless.

[20] Mild haemophiliacs often manage their condition with desmopressin, a drug which releases stored factor VIII from blood vessel walls.

[21] If numbing is necessary for dental procedures, the nerve block (typically to the inferior alveolar nerve) should only be given after raising clotting factor levels by appropriate replacement therapy, as there is a risk of bleeding into the muscles along with potential airway compromise due to a haematoma in the retromolar or pterygoid space.

A lingual infiltration also requires appropriate factor replacement since the injection is into an area with a rich plexus of blood vessels and the needle is not adjacent to bone.

[28] In July 2024, a recent study published in the New England Journal of Medicine demonstrated that efanesoctocog alfa, a bioengineered human factor VIII recombinant protein, prophylaxis for children with severe hemophilia A could have therapeutic benefit leading to effective bleeding prevention.

[31][32] Both studies found that viral infections were common in haemophiliacs due to the frequent blood transfusions which put them at risk of acquiring blood borne infections, such as HIV, hepatitis B and hepatitis C. In the latest study which followed patients from 1992 to 2001, the male life expectancy was 59 years.

26% of the cases died from AIDS and 22% from hepatitis C.[32] However, these statistics for prognosis are unreliable as there has been marked improvement of infection control and efficacy of anti-retroviral drugs since these studies were done.