The symptoms can either be mild or severe. They may begin suddenly or increase over time depending on the size of the embolus and how much blood flow is compromised. Symptoms also depend on the organ involved but generally involves pain and loss of function.

• Pulmonary embolism will present as sharp chest pain, shortness of breath, wheezing, cough, bloody sputum and lightheadedness. These symptoms usually appear suddenly.
• Myocardial infarction will present with symptoms like chest pain, anxiety, excessive sweating, shortness of breath and palpitations. 
• Stroke will present with headache, fainting and loss of consciousness.
• If the infarction occurs in a limb, there would be pain on the affected limb, no pulse beyond the location of the blockage, numbness, tingling, muscle weakness and gangrene [6].

• Inflammation

  In the brain, these fat micro globules produce irritation and inflammation in the walls of the small vessels, or capillaries. [parentprojectmd.org]

  When a clot or embolus blocks a major or deep vein, blood pools behind the obstruction, causing inflammation. Though they can occur anywhere, most cases of venous thrombosis develop in the deep veins of the lower legs. [healthline.com]

  These symptoms include: Pain, inflammation or warmth in one of your legs Skin that is red or discolored on one of your legs Swelling in one leg or along one leg vein Sores or ulcers on your leg Learn more about deep vein thrombosis, sometimes also called [aurorahealthcare.org]

  Estrogen stored in fatty tissue can contribute to clot formation, inflammation and other problems that can trigger development of a potentially dangerous clot. [draxe.com]

  By Lara DeSanto A new study out of the University of California at San Francisco found that older adults who used a skin cream twice a day for a month had lower levels of inflammation throughout their bodies. Here’s what you need to know. [healthafter50.com]

• Gangrene

  Embolism plays an important part in determining one form of gangrene, as has already been described. [thesaurus.com]

  […] anterior inferior) (posterior inferior) (superior) 433.8 cerebral (see also Embolism, brain) 434.1 choroidal (anterior) 433.8 communicating posterior 433.8 coronary (see also Infarct, myocardium) 410.9 extremity 444.22 hypophyseal 433.8 mesenteric (with gangrene [icd9data.com]

  If the infarction occurs in a limb, there would be pain on the affected limb, no pulse beyond the location of the blockage, numbness, tingling, muscle weakness and gangrene. [symptoma.com]

  Manifestations may include painful blue toes, gangrene of the lower extremities, skin discoloration, kidney failure, abdominal pain, intestinal bleeding, stroke, or peripheral nerve disease. [verywellhealth.com]

• Pneumonia

  Figure 1: Figure 2: Images in a 70-year-old man with COVID-19 pneumonia. [pubs.rsna.org]

  A COVID-19-positive 75-year-old woman, with severe bilateral pneumonia and concomitant acute pulmonary embolism, was hospitalized after 10 days of fever and a recent onset of dyspnoea. [academic.oup.com]

  The patient developed pneumonia and status epilepticus, and died 24 days after the endovascular procedure, most likely as a result of the sequelae of the aneurysm rupture. [ncbi.nlm.nih.gov]

  With symptoms that resemble many other medical conditions, including heart attack and pneumonia, it can be difficult to diagnose. [yalemedicine.org]

  When to suspect FES The symptoms of FES can be very nonspecific, making them easily missed or attributed to something else (such as pneumonia or another illness). [parentprojectmd.org]

• Abdominal Pain

  The patient was admitted to our center with diffuse abdominal pain that was more pronounced in the right iliac fossa. [revespcardiol.org]

  Manifestations may include painful blue toes, gangrene of the lower extremities, skin discoloration, kidney failure, abdominal pain, intestinal bleeding, stroke, or peripheral nerve disease. [verywellhealth.com]

  Other symptoms of bleeding to watch for include: Signs of bleeding in the digestive system: Bright red vomit or vomit that looks like coffee grounds Bright red blood in your stool or black, tarry stools Abdominal pain Signs of bleeding in the brain: Severe [urmc.rochester.edu]

• Vomiting

  Other symptoms of bleeding to watch for include: Signs of bleeding in the digestive system: Bright red vomit or vomit that looks like coffee grounds Bright red blood in your stool or black, tarry stools Abdominal pain Signs of bleeding in the brain: Severe [urmc.rochester.edu]

  Symptoms Shortness of breath that comes on suddenly Chest pain that gets worse when you breathe deeply or cough Coughing or vomiting blood When to See a Doctor If you experience symptoms of pulmonary embolism, call 911 and get medical help immediately [intermountainhealthcare.org]

• Nausea

  Seek immediate medical attention if you have symptoms of arterial thrombosis including: chest pain that often comes on randomly, such as when you’re resting, and won’t respond to medication shortness or loss of breath sweating nausea a limb or area of [healthline.com]

  Depending on the sensitivity of your skin, some of the side effects to expect include: Reddening of the skin Mild irritation Dry skin Scaling With oral use, it is possible to experience: Nausea Diarrhoea Abdominal discomfort Bloating Allergic skin rash [beskinformed.com]

  CRUSH INJURY Symptoms: Signs: Dizziness Pale, cold and clammy skin Faintness Pulse slow at first - rapid and feeble Nausea Resps shallow and rapid Thirst Altered consc. level - coma When muscle tissue is severely compressed, as in a crush injury, the [medenosrce.net]

  […] patient was prespecified in the study protocol and was based on the 2014 guidelines of the European Society of Cardiology. 5 A medical history was obtained that included the presence of prodromal symptoms of autonomic activation (sweating, pallor, or nausea [nejm.org]

• Heart Disease

  In contrast to heart disease, it is therefore rare for lung cancers to suddenly turn into medical emergencies. [herzzentrum.immanuel.de]

  Certain health conditions – such as obesity, heart disease, cancer and pregnancy – can cause blood clots to form inside your veins even where there's no bleeding. [nhs.uk]

  Causes: Risk factors for formation on clots include heart disease, cancer, pregnancy, obesity, increased cholesterol, hypertension and advancing age. [symptoma.com]

  You may be at risk if you: smoke tobacco products have high blood pressure have had recent surgery have heart disease eat a diet high in cholesterol have an abnormally fast heart rate are obese live a sedentary lifestyle are of advanced age Your doctor [healthline.com]

  If you have lung or heart disease, that can play a role, too. PE Is a Medical Emergency Symptoms of PE tend to come on suddenly. [webmd.com]

• Heart Murmur

  Heart murmurs can be present, but may be more reflective of primary valvular disease rather than IE itself [7]. [intechopen.com]

  Tachycardia, tachypnea, and hypotension are frequently discovered on physical examination, and occasionally, a relatively specific drumlike or “mill wheel” heart murmur is heard [6, 11, 14, 17]. [ajronline.org]

• Diplopia

  Focal neurological symptoms (hemiparesis, facial droop, diplopia, aphasia, vertigo) are present in approximately 40% of affected patients, and nonfocal presentations (headaches, seizures, altered mental status) occur in approximately one-third of cases [intechopen.com]

• Fidgeting

  Fidget in your seat. Flex your ankles every 15 to 30 minutes. Wear support stockings. Your doctor may recommend these to help promote circulation and fluid movement in your legs. [mayoclinic.org]

• Intracranial Hemorrhage

  The four major categories of cerebrovascular disease are atherosclerotic thrombosis, cerebral embolism, lacunae and intracranial hemorrhage. [dictionary.cambridge.org]

  Systemic thrombolysis carries a 20 percent risk of major hemorrhage and a 3-5 percent risk of intracranial hemorrhage. [dicardiology.com]

  Both routes carry an increased risk of hemorrhage compared with standard anticoagulation. [clevelandclinicmeded.com]

  Absolute contraindications to thrombolytics include Prior hemorrhagic stroke Ischemic stroke within 1 yr Active external or internal bleeding from any source Intracranial injury or surgery within 2 mo Intracranial tumor Certain surgeries within the previous [merckmanuals.com]

  Intracranial hemorrhage complicating acute stroke: how common is hemorrhagic stroke on initial head CT scan and how often is initial clinical diagnosis of acute stroke eventually confirmed?. AJNR Am J Neuroradiol. 2005 Oct. 26(9):2207-12. [Medline]. [medscape.com]

• Vertigo

  Focal neurological symptoms (hemiparesis, facial droop, diplopia, aphasia, vertigo) are present in approximately 40% of affected patients, and nonfocal presentations (headaches, seizures, altered mental status) occur in approximately one-third of cases [intechopen.com]

• Quadriplegia

  […] male, 4 female) who were hospitalized in Trauma and Surgical Emergency Service of Istanbul Medical Faculty. 10 of the VCF used were permanent and 2 of them were temporary filters. 8 permanent filter were applied to patients with life-long paraplegia or quadriplegia [tjtes.org]

There are various investigations that can be done to check for the presence of an embolus, the extent of damage of an embolus and the risk of developing an embolus.

• Ultrasound, especially colored Doppler ultrasound is used to examine the arteries, it can also be applied through the transcranial route. 
• MRI and CT scan of the brain with contrast to show the area of the infarct and the level of damage done to the brain. 
• Echocardiography and electrocardiography is used to diagnose a myocardial infarction. Specialized techniques like transesophageal echocardiography may be involved [7].
• Arteriography can also be done and when the use of contrast is required to be kept to a minimum, digital subtraction angiography is used.
• Angioscopy is used to visualize the artery directly by passing a flexible catheter into it.
• Blood tests are done to measure the level of enzymes on the body. Many of these enzymes are increased in embolization especially of the heart. Blood tests will also show if there are any underlying infection. Blood tests are also used to test for coagulation factors.

The goal of treatment is to minimize symptoms and increase perfusion to the affected area. It involves the use of thrombolytics to dissolve the clot, anticoagulants like heparin to thin the blood and prevent further clotting. Painkillers are giving to reduce the pain and vasodilators to relax and dilate the blood vessels.

Sometimes, surgery may be indicated and this includes, embolectomy which is done to reduce the embolus and arterial bypass surgery done to create a new blood supply [8]. In cases where the limb is affected and it has developed to gangrene, the affected limb should be amputated.

The prognosis of a patient depends on the area affected by the clot and the extent to which blood flow is compromised. If medical intervention is not sought, mortality rate is as high as 30%. The affected part could also be permanently damaged leading to loss of that part, e.g in amputation. There is a chance of recurrence of this condition even after successful treatment [5].

In normal individuals, clotting factors are responsible for prevention of excessive blood loss when there is a bleeding episode. In some individuals, formation of blood clots happen even without a bleeding episode, these individuals are said to be at risk of clot formation. Some of the risk factors for clot formation are heart disease, hypercholesterolemia, smoking, hypertension, and atherosclerosis.

Another cause is stasis of blood flow. This could lead to clots and it is the primary cause of pulmonary embolism. Factors that contribute to this are sitting on long flights, prolonged best rest, immobilization of the leg, cancer, previous surgery and some genetic conditions that predispose an individual to clot formation [2].

Over 500,000 deaths result each year from heart-related condition caused by arterial embolism, and half of these are women. Half of these deaths are in individuals who have not reached their life expectancy. Venous thromboembolism also occurs in as much as 100 per 100,000 individuals with the incidence increasing with age to as high as 600 in 100,000 in those above 80 years. Death occurs in about 6% of deep venous thrombosis (DVT) cases and the incidence is equal in both male and females. Embolism is slightly commoner in Caucasians and Negroes than in Hispanics and Asians[3].

Due to some of the factors listed above, a clot begins to form in a vessel. This clot is known as a thrombus. The thrombus then dislodges and begins to travel within the circulation, mostly in the direction of blood flow and is now called an embolus. When it gets to a vessel it is too big to pass through, it lodges and blocks the lumen preventing further blood flow. This will lead to ischemia of the supplied area as oxygen supply is compromised leading to tissue hypoxia and eventually necrosis. The specific pathophysiology depends on the organs and areas supplied [4].

This involves reducing the risk factors and steps include healthy diet, avoid excessive salt in diet, losing weight if overweight or obese, regular exercise, stop smoking.

The most important conditions that result from an embolism are stroke, myocardial infarction and pulmonary embolism. The symptoms of embolism are usually very acute and prompt medical intervention is required [1].

• Definition: When a blood clot forms in within an intact vein or artery, it is called a thrombus. When this clot dislodges, it is called an embolus. Embolism is what results when this embolus travels and blocks the blood supply to a particular part of the body or organ like heart or lungs.
• Causes: Risk factors for formation on clots include heart disease, cancer, pregnancy, obesity, increased cholesterol, hypertension and advancing age. Also, anything that can cause long periods of immobility e.g long flights and prolonged bed rest can lead to formation of clots.
• Symptoms: These are generally specific for the organs affected. They include pain and loss of function. There is chest pain, cough and shortness of breath in myocardial infarction and pulmonary embolism while stroke may present with unconsciousness and paralysis.
• Diagnosis: These involve a series of imaging tests and blood tests. These are used to know where the clot is and the extent of damage.
• Treatment: This involves the use of drugs to melt the clots and prevent further clots from forming and pain killers to manage the pain. Surgery may also be indicated to remove the clot or a bypass surgery to restore blood flow.

1. Bates SM, Greer IA, Pabinger I, Sofaer S, Hirsh J. Venous thromboembolism, thrombophilia, antithrombotic therapy, and pregnancy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest. Jun 2008;133(6 suppl):844S-886S.
2. Couturaud F, Leroyer C, Julian JA, et al. Factors that predict risk of thrombosis in relatives of patients with unprovoked venous thromboembolism. Chest. Jul 10 2009;epub ahead of print.
3. Roberts LN, Patel RK, Arya R. Venous thromboembolism and ethnicity. Br J Haematol. Aug 2009;146(4):369-83.
4. Kearon C, Julian JA, Kovacs MJ, et al. Influence of thrombophilia on risk of recurrent venous thromboembolism while on warfarin: results from a randomized trial. Blood. Dec 1 2008;112(12):4432-6.
5. Perez A, Merli GJ. Novel Anticoagulant Use for Venous Thromboembolism: A 2013 Update. Curr Treat Options Cardiovasc Med. Feb 6 2013
6. Qaseem A, Snow V, Barry P, Hornbake ER, Rodnick JE, Tobolic T, et al. Current diagnosis of venous thromboembolism in primary care: a clinical practice guideline from the American Academy of Family Physicians and the American College of Physicians. Ann Fam Med. Jan-Feb 2007;5(1):57-62.
7. Geerts WH, Code KI, Jay RM, Chen E, Szalai JP. A prospective study of venous thromboembolism after major trauma. N Engl J Med. Dec 15 1994;331(24):1601-6. 
8. Garcia D, Ageno W, Libby E. Update on the diagnosis and management of pulmonary embolism. Br J Haematol. Nov 2005;131(3):301-12.