Treatment can be either conservative or active. Active treatments can be divided into surgical and non-surgical treatments. Newer methods including endovenous laser treatment, radiofrequency ablation and foam sclerotherapy appear to work as well as surgery for varices of the greater saphenous vein.

The National Institute for Health and Clinical Excellence (NICE) produced clinical guidelines in July 2013 recommending that all people with symptomatic varicose veins (C2S) and worse should be referred to a vascular service for treatment. Conservative treatments such as support stockings should not be used unless treatment was not possible.

The symptoms of varicose veins can be controlled to an extent with the following:

- Elevating the legs often provides temporary symptomatic relief.

- Advice about regular exercise sounds sensible but is not supported by any evidence.

- The wearing of graduated compression stockings with variable pressure gradients (Class II or III) has been shown to correct the swelling, nutritional exchange, and improve the microcirculation in legs affected by varicose veins. They also often provide relief from the discomfort associated with this disease. Caution should be exercised in their use in patients with concurrent peripheral arterial disease.

- The wearing of intermittent pneumatic compression devices have been shown to reduce swelling and increase circulation

- Diosmin/hesperidin and other flavonoids.

- Anti-inflammatory medication such as ibuprofen or aspirin can be used as part of treatment for superficial thrombophlebitis along with graduated compression hosiery – but there is a risk of intestinal bleeding. In extensive superficial thrombophlebitis, consideration should be given to anti-coagulation, thrombectomy, or sclerotherapy of the involved vein.

- Topical gel application helps in managing symptoms related to varicose veins such as inflammation, pain, swelling, itching, and dryness.

Conservative treatment of CVI in the leg involves symptomatic treatment and efforts to prevent the condition from getting worse instead of effecting a cure. This may include

- Manual compression lymphatic massage therapy

- Skin lubrication

- Sequential compression pump

- Ankle pump

- Compression stockings

- Blood pressure medicine

- Frequent periods of rest elevating the legs above the heart level

- Tilting the bed so that the feet are above the heart. This may be achieved by using a 20 cm (7-inch) bed wedge or sleeping in a 6 degree Trendelenburg position. Obese or pregnant patients might be advised by their physicians to forgo the tilted bed.

Venous Insufficiency Conservative, Hemodynamic and Ambulatory treatment" is an ultrasound guided, minimally invasive surgery strategic for the treatment of varicose veins, performed under local anaesthetic. CHIVA is an abbreviation from the French "Cure Conservatrice et Hemodynamique de l'Insufficience Veineuse en Ambulatoire".

Pentoxifylline is a useful add on treatment to compression stockings and may also help by itself. It works by reducing platelet aggregation and thrombus formation. Gastrointestinal disturbances were reported as a potential adverse effect.

Sulodexide, which reduces the formation of blood clots and reduces inflammation, may improve the healing of venous ulcers when taken in conjunction with proper local wound care. Further research is necessary to determine potential adverse effects, the effectiveness, and the dosing protocol for sulodexide treatment.

An oral dose of aspirin is being investigated as a potential treatment option for people with venous ulcers. A 2016 Cochrane systematic review concluded that further research is necessary before this treatment option can be confirmed to be safe and effective.

Oral zinc supplements have not been proven to be effective in aiding the healing of venous ulcers, however more research is necessary to confirm these results.

Non-elastic, ambulatory, below knee (BK) compression counters the impact of reflux on venous pump failure. Compression therapy is used for venous leg ulcers and can decrease blood vessel diameter and pressure, which increases their effectiveness, preventing blood from flowing backwards. Compression is also used to decrease release of inflammatory cytokines, lower the amount of fluid leaking from capillaries and therefore prevent swelling, and prevent clotting by decreasing activation of thrombin and increasing that of plasmin. Compression is applied using elastic bandages or boots specifically designed for the purpose.

Regarding effectiveness, compression dressings improve healing. It is not clear whether non-elastic systems are better than a multilayer elastic system. Patients should wear as much compression as is comfortable. The type of dressing applied beneath the compression does not seem to matter, and hydrocolloid is not better than simple low adherent dressings. Recently there have been clinical studies on a multi-functional botanical-based ointment in combination with compression therapy in the treatment of difficult-to-heal wounds, including venous leg ulcers.

Intermittent pneumatic compression devices may be used, but it is not clear that they are superior to simple compression dressings.

It is not clear if interventions that are aimed to help people adhere to compression therapy are effective. More research is needed in this field.

Prevention of PTS begins with prevention of initial and recurrent DVT. For people hospitalized at high-risk of DVT, prevention methods may include early ambulation, use of compression stockings or electrostimulation devices, and/or anticoagulant medications.

Increasingly, catheter-directed thrombolysis has been employed. This is a procedure in which interventional radiology will break up a clot using a variety of methods.

For people who have already had a single DVT event, the best way to prevent a second DVT is appropriate anticoagulation therapy.

A second prevention approach may be weight loss for those who are overweight or obese. Increased weight can put more stress and pressure on leg veins, and can predispose patients to developing PTS.

Treatment options for PTS include proper leg elevation, compression therapy with elastic stockings, or electrostimulation devices, pharmacotherapy (pentoxifylline), herbal remedies (such as horse chestnut, rutosides), and wound care for leg ulcers.

The benefits of compression bandages is unclear. They may be useful to treat edemas.

In terms of treatment for this condition the individual may be advised to do the following: "raise" the affected area to decrease swelling, and relieve pressure off of the affected area so it will encounter less pain. In certain circumstances drainage of the clot might be an option. In general, treatment may include the following:

Anticoagulation, which prevents further coagulation, but does not act directly on existing clots, is the standard treatment for DVT. Balancing risk vs. benefit is important in determining the duration of anticoagulation, and three months is generally the standard length of treatment. In those with an annual risk of VTE in excess of 9%, as after an unprovoked episode, extended anticoagulation is a possibility. Those who finish VKA treatment after idiopathic VTE with an elevated D-dimer level show an increased risk of recurrent VTE (about 9% vs about 4% for normal results), and this result might be used in clinical decision-making. Thrombophilia test results rarely play a role in the length of treatment.

For acute cases in the leg, the ACCP recommended a parenteral anticoagulant (such as LMWH, fondaparinux, or unfractionated heparin) for at least five days and a VKA, the oral anticoagulant, the same day. LMWH and fondaparinux are suggested over unfractionated heparin, but both are retained in those with compromised kidney function, unlike unfractionated heparin. The VKA is generally taken for a minimum of three months to maintain an international normalized ratio of 2.0–3.0, with 2.5 as the target. The benefit of taking a VKA declines as the duration of treatment extends, and the risk of bleeding increases with age.

The ACCP recommended treatment for three months in those with proximal DVT provoked by surgery. A three-month course is also recommended for those with proximal DVT provoked by a transient risk factor, and three months is suggested over lengthened treatment when bleeding risk is low to moderate. Unprovoked DVT patients should have at least three months of anticoagulation and be considered for extended treatment. Those whose first VTE is an unprovoked proximal DVT are suggested for anticoagulation longer than three months unless there is a high risk of bleeding. In that case, three months is sufficient. Those with a second unprovoked VTE are recommended for extended treatment when bleeding risk is low, suggested for extended treatment when bleeding risk is moderate, and suggested for three months of anticoagulation in high-risk scenarios.

The ACCP recommended initial home treatment instead of hospital treatment for those with acute leg DVT. This applies as long as individuals feel ready for it, and those with severe leg symptoms or comorbidities would not qualify. An appropriate home environment is expected: one that can provide a quick return to the hospital if necessary, support from family or friends, and phone access.

In addition to anticoagulation, the ACCP suggested graduated compression stockings—which apply higher pressure (30–40 mm Hg) at the ankles and a lower pressure around the knees—for those with symptomatic DVT. Use should begin as soon as possible after anticoagulation. Evidence however does not support that these stockings reduce the risk of post-thrombotic syndrome nor do they indicate a reduction in recurrent VTE. Use is suggested for two years, though inconvenience and discomfort can reduce compliance. Walking is also suggested for those without severe pain or edema.

Unless a person has medical problems preventing movement, after a person starts anti-coagulation therapy bed rest should not be used to treat acute deep vein thrombosis. There are clinical benefits associated with walking and no evidence that walking is harmful, but people with DVT are harmed by bed rest except when it is medically necessary.

Instead of anticoagulation, a follow-up imaging test (typically ultrasound) about one-week post-diagnosis is an option for those with an acute isolated distal DVT without a high risk for extension; if the clot does not grow, the ACCP does not recommend anticoagulation. This technique can benefit those at a high risk for bleeding. Patients may choose anticoagulation over serial imaging, however, to avoid the inconvenience of another scan if concerns about the risk of bleeding are insignificant. When applied to symptomatic patients with a negative initial ultrasound result, serial testing is inefficient and not cost effective.

Preventing the development of blood clots in the upper extremities is done by accessing the risk of the development of such clots.The traditional treatment for thrombosis is the same as for a lower extremity DVT, and involves systemic anticoagulation to prevent a pulmonary embolus. Some have also recommended thrombolysis with catheter directed alteplase. If there is thoracic outlet syndrome or other anatomical cause then surgery can be considered to correct the underlying defect.

Before any treatment of leg telangectasia (spider veins) is considered, it is essential to have duplex ultrasonography, the test that has replaced Doppler ultrasound. The reason for this is that there is a clear association between leg telangectasia (spider veins) and underlying venous reflux. Research has shown that 88-89% of women with telangectasia (spider veins) have refluxing reticular veins close, and 15% have incompetent perforator veins nearby. As such, it is essential to both find and treat underlying venous reflux before considering any treatment at all.

Sclerotherapy is the "gold standard" and is preferred over laser for eliminating telangiectasiae and smaller varicose leg veins. A sclerosant medication is injected into the diseased vein so it hardens and eventually shrinks away. Recent evidence with foam sclerotherapy shows that the foam containing the irritating sclerosant quickly appears in the patient's heart and lungs, and then in some cases travels through a patent foramen ovale to the brain. This has led to concerns about the safety of sclerotherapy for telangectasias and spider veins.

In some cases stroke and transient ischemic attacks have occurred after sclerotherapy. Varicose veins and reticular veins are often treated before treating telangiectasia, although treatment of these larger veins in advance of sclerotherapy for telangiectasia may not guarantee better results. Varicose veins can be treated with foam sclerotherapy, endovenous laser treatment, radiofrequency ablation, or open surgery. The biggest risk, however, seems to occur with sclerotherapy, especially in terms of systemic risk of DVT, pulmonary embolism, and stroke.

Other issues which arise with the use of sclerotherapy to treat spider veins are staining, shadowing, telangetatic matting, and ulceration. In addition, incompleteness of therapy is common, requiring multiple treatment sessions.

Telangiectasias on the face are often treated with a laser. Laser therapy uses a light beam that is pulsed onto the veins in order to seal them off, causing them to dissolve. These light-based treatments require adequate heating of the veins. These treatments can result in the destruction of sweat glands, and the risk increases with the number of treatments.

Recommendations for those without cancer include anticoagulation (stopping further blood clots from forming) with dabigatran, rivaroxaban, apixaban, or edoxaban rather than warfarin or low molecular weight heparin (LMWH). For those with cancer LMWH is recommended. For initial treatment of VTE, fixed doses with LMWH may be more effective than adjusted doses of unfractionated heparin (UFH) in reducing blood clots. No differences in mortality, prevention of major bleeding, or preventing VTEs from recurring were observed between LMWH and UFH. No differences have been detected in the route of administration of UFH (subcutaneous or intravenous). LMWH is usually administered by a subcutaneous injection, and a persons blood clotting factors do not have to be monitored as closely as with UFH. People with cancer have a higher risk of experiencing reoccurring VTE episodes ("recurrent VTE"), despite taking preventative anticoagulation medication. These people should be given therapeutic doses of LMWH medication, either by switching from another anticoagulant or by taking a higher dose of LMWH.

For those with a small pulmonary embolism and few risk factors, no anticoagulation is needed. Anticoagulation is; however, recommended in those who do have risk factors. Thrombolysis is recommended in those with PEs that are causing low blood pressure.

Treatment usually consists of NSAIDs, such as ibuprofen and local compression (e.g., by compression stockings or a compress). If the phlebitis is associated with local bacterial infection, antibiotics may be used.

For acute infusion superficial thrombophlebitis, not enough evidence exists as of 2015 to determine treatment.

Inferior vena cava filters (IVCFs) are not recommended in those who are on anticoagulants. IVCFs may be used in clinical situations where a person has a high risk of experiencing a pulmonary embolism, but cannot be on anticoagulants due to a high risk of bleeding, or they have active bleeding. Retrievable IVCFs are recommended if IVCFs must be used, and a plan should be created to remove the filter when it is no longer needed.

Treatment may consist of topical applications of steroid based creams and the use of compression stockings to help force the underlying buildup of fluids back out of the lower leg or intermittent pneumatic compression pumps.

Warfarin and vitamin K antagonists are anticoagulants that can be taken orally to reduce thromboembolic occurrence. Where a more effective response is required, heparin can be given (by injection) concomitantly. As a side effect of any anticoagulant, the risk of bleeding is increased, so the international normalized ratio of blood is monitored. Self-monitoring and self-management are safe options for competent patients, though their practice varies. In Germany, about 20% of patients were self-managed while only 1% of U.S. patients did home self-testing (according to one 2012 study). Other medications such as direct thrombin inhibitors and direct Xa inhibitors are increasingly being used instead of warfarin.

Arterial thrombosis is platelet-rich, and inhibition of platelet aggregation with antiplatelet drugs such as aspirin may reduce the risk of recurrence or progression.

Prevention consists of walking, drinking fluids and if currently hospitalized, changing of IV lines. Walking is especially suggested after a long period seated, particularly when one travels.

In ideal circumstances, patients with known varices should receive treatment to reduce their risk of bleeding. The non-selective β-blockers (e.g., propranolol, timolol or nadolol) and nitrates (e.g., isosorbide mononitrate (IMN) have been evaluated for secondary prophylaxis. Non-selective β-blockers (but not cardioselective β-blockers like atenolol) are preferred because they decrease both cardiac output by β blockade and splanchnic blood flow by blocking vasodilating β receptors at splanchnic vasculature. The effectiveness of this treatment has been shown by a number of different studies.

However, non-selective β-blockers do not prevent the "formation" of esophageal varices.

When medical contraindications to beta-blockers exist, such as significant reactive airway disease, then treatment with prophylactic endoscopic variceal ligation is often performed.

In emergency situations, care is directed at stopping blood loss, maintaining plasma volume, correcting disorders in coagulation induced by cirrhosis, and appropriate use of antibiotics such as quinolones or ceftriaxone. Blood volume resuscitation should be done promptly and with caution. The goal should be hemodynamic stability and hemoglobin of over 8 g/dl. Resuscitation of all lost blood leads to increase in portal pressure leading to more bleeding. Volume resuscitation can also worsen ascites and increase portal pressure. (AASLD guidelines)

Therapeutic endoscopy is considered the mainstay of urgent treatment. The two main therapeutic approaches are variceal ligation or banding and sclerotherapy.

In cases of refractory bleeding, balloon tamponade with a Sengstaken-Blakemore tube may be necessary, usually as a bridge to further endoscopy or treatment of the underlying cause of bleeding (usually portal hypertension). Esophageal devascularization operations such as the Sugiura procedure can also be used to stop complicated variceal bleeding. Methods of treating the portal hypertension include: transjugular intrahepatic portosystemic shunt, or a distal splenorenal shunt procedure or a liver transplantation.

Nutritional supplementation is not necessary if the patient is not eating for four days or less.

Terlipressin and octreotide for 1 to 5 days have also been used.

It is sometimes treated with surgery, which involves rerouting blood from the right atrium into the left atrium with a patch or use of the Warden procedure. However, interest is increasing in catheter-based interventional approaches, as well as medical therapy for less severe cases.

An acute nosebleed may be managed with a variety of measures, such as packing of the nasal cavity with absorbent swabs or gels. Removal of the packs after the bleeding may lead to reopening of the fragile vessels, and therefore lubricated or atraumatic packing is recommended. Some patients may wish to learn packing themselves to deal with nosebleeds without having to resort to medical help.

Frequent nosebleeds can be prevented in part by keeping the nostrils moist, and by applying saline solution, estrogen-containing creams or tranexamic acid; these have few side effects and may have a small degree of benefit. A number of additional modalities has been used to prevent recurrent bleeding if simple measures are unsuccessful. Medical therapies include oral tranexamic acid and estrogen; the evidence for these is relatively limited, and estrogen is poorly tolerated by men and possibly carries risks of cancer and heart disease in women past the menopause. Nasal coagulation and cauterization may reduce the bleeding from telangiectasias, and is recommended before surgery is considered. However, it is highly recommended to use the least heat and time to prevent septal perforations and excessive trauma to the nasal mucosa that are already susceptible to bleeding. Sclerotherapy is another option to manage the bleeding. This process involves injecting a small amount of an aerated irritant (detergent such as sodium tetradecyl sulfate) directly into the telangiectasias. The detergent causes the vessel to collapse and harden, resulting in scar tissue residue. This is the same procedure used to treat varicose veins and similar disorders.

It may be possible to embolize vascular lesions through interventional radiology; this requires passing a catheter through a large artery and locating the maxillary artery under X-ray guidance, followed by the injection into the vessel of particles that occlude the blood vessels. The benefit from the procedure tends to be short-lived, and it may be most appropriate in episodes of severe bleeding.

To more effectively minimize recurrence and severity of epistaxis, other options may be used in conjunction with therapies listed above. Intravenously administered anti-VEGF substances such as bevacizumab (brand name Avastin), pazopinab and thalidomide or its derivatives interfere with the production of new blood vessels that are weak and therefore prone to bleeding. Due to the past experiences with prescribing thalidomide to pregnant women to alleviate symptoms of nausea and the terrible birth defects that followed, thalidomide is a last resort therapy. Additionally, thalidomide can cause neuropathy. Though this can be mitigated by tinkering with dosages and prescribing its derivatives such as lenolidomide and pomalidomide, many doctors prefer alternative VEGF inhibitors. Bevacizumab has been shown to significantly reduce the severity of epistaxis without side effects.

If other interventions have failed, several operations have been reported to provide benefit. One is septal dermoplasty or Saunders' procedure, in which skin is transplanted into the nostrils, and the other is Young's procedure, in which the nostrils are sealed off completely.

The skin lesions of HHT can be disfiguring, and may respond to treatment with long-pulsed . Skin lesions in the fingertips may sometimes bleed and cause pain. Skin grafting is occasionally needed to treat this problem.

With regards to digestive tract lesions, mild bleeding and mild resultant anemia is treated with iron supplementation, and no specific treatment is administered. There is limited data on hormone treatment and tranexamic acid to reduce bleeding and anemia. Severe anemia or episodes of severe bleeding are treated with endoscopic argon plasma coagulation (APC) or laser treatment of any lesions identified; this may reduce the need for supportive treatment. The expected benefits are not such that repeated attempts at treating lesions are advocated. Sudden, very severe bleeding is unusual—if encountered, alternative causes (such as a peptic ulcer) need to be considered—but embolization may be used in such instances.