Circulatory System Diseases (descriptions, causes and effects)

Cardiovascular Disease / Disorder

What is it ?

Can be caused by ...

Effects / Symptoms

Anaemia

A reduction in the quantity of (oxygen-carrying) haemoglobin in the blood and/or bellow normal quantity of red blood cells.

The many possible causes include:

• Haemorrhagic anaemia - due to loss of blood
• Iron-deficiency anaemia - due to insuffiicent iron, often due to dietary deficiency.
• Haemolytic anaemias result from the increased destruction of red blood cells e.g. due to toxic chemicals, autoimmunity, the action of parasites, abnormal forms of haemoglobin or abnormal red blood cells.
• Anaemia can also be caused by the impaired production of red blood cells, as in leukaemia (when red blood cell production in the bone marrow is suppressed) or pernicious anaemia.

Main symptoms are:

• Excessive tiredness
• Breathlessness on exertion
• Pallor (i.e. looking pale, esp. on face and palms)
• Low resistance to infection

Angina

Pain after physical effort due to ...

narrowed coronary arteries being unable to supply increased blood flow required for increased physical exertion. (The arteries may have been narrowed by the accumulation of atheromatous plaque - see atherosclerosis, below.)

Typical symptoms include short-term discomfort such as an ache, pain or tightness across the front of the chest when or immediately following exertion or other situations in which heart rate is increased e.g. due to panic or an argument. Other less common effects & symptoms are also possible e.g. similar pain when or soon after eating.

Aneurysm

Balloon-like bulge or swelling in the wall of an artery

In general, causes can be genetic or due to disease, e.g.

• a degenerative disease
• a syphilitic infection - causing damage to the muscular coat of the blood vessel
• a congenital deficiency in the muscular wall

Aneurysms can cause the wall of the blood vessel to weaken. When an aneurysm gets bigger the risk of rupture increases. That can lead to severe haemorrhage (bleeding), other complications - some of which may be life-threatening.

Arteriosclerosis

Hardening of the arteries.
(Arteriolosclerosis is the hardening of arterioles.)

Artery walls thicken, stiffen and lose elasticity, a progressive condition that typically worsens over time unless action is taken to address it.

Note: Healthy arteries are flexible and elastic.

High blood pressure (also known as hypertension) is widely cited as a cause of, or at least a contributory factor to, the development of arteriosclerosis.

To reduce risk, keep blood pressure within a healthy range. See also how to reduce risk of atherosclerosis (below).

Arteriosclerosis (in combination with atherosclerosis or otherwise) can reduce the flow of blood, hence the supply of oxygen, nutrients etc., to tissues in the affected area.

Arteriosclerosis can affect any artery in the body but is of greatest concern when occurs in the heart (coronary arteries) or the brain.

Atherosclerosis (Atheroma)

- a common type of arteriosclerosis (see above)

Artery wall(s) thicken as a result of the accumulation of fatty materials forming a plaque.

• Multiple fatty plaques (consisting of e.g. cholesterol and triglyceride) accumulate on the inner walls of arteries.

To reduce risk:

1. Eat sensibly (see balanced diet)
2. Don't smoke
3. Take appropriate regular exercise
4. Maintain a healthy body weight
5. Do not consume excessive alcohol

A chronic disease that can remain asymptomatic for decades. However, blood flow is restricted and eventually obstructed.
Various complications of advanced atherosclerosis are possible. One of the most significant risks is of an infarction due to soft plaque suddenly rupturing, causing the formation of a thrombus (blood clot) that can slow or stop blood flow- leading to death of the tissues fed by the artery. Thrombosis of a coronary artery can cause a heart attack (Myocardial infarction). The same process in an artery to the brain is commonly called stroke.

Arteriosclerosis vs Atherosclerosis?

Someone who has arteriosclerosis (hardened arteries) might, or might not, also have atherosclerosis (plaque in arteries).
A person who has atherosclerosis does have arteriosclerosis; atherosclerosis is a common type of arteriosclerosis.

Which happens first ? - There is no single sequence that applies in all cases.
Atherosclerosis can cause arteriosclerosis, typically in larger arteries.
Arteriosclerosis (hardening of arteries) can occur due to high blood pressure and never lead to atherosclerosis, e.g. because the person's diet is not high in the type of fatty substances that may eventually form plaque in arteries (i.e. atherosclerosis).

Coronary thrombosis

See also 20. Thrombus

A thrombus is a blood clot. Thrombosis is a condition in which blood changes from a liquid into a solid state, producing a 'clot' (thrombus). Coronary thrombosis is the condition in which the thrombus is formed in one of the 3 major coronary arteries that supply the heart.

Coronary thrombosis can occur due to the accumulation of fatty deposits (plaques) inside the arteries, i.e. atherosclerosis. The hardening of arteries (arteriosclerosis) can also contribute to reduced blood flow leading to coronary thrombosis.

Risk factors are similar to those listed elsewhere on this page for related conditions, including e.g.

• family history of atherosclerosis
• high blood cholesterol level
• high blood pressure (hypertension)
• smoking
• Diabetes (Type 1 or Type 2)
• being overweight, esp. obese
• taking insufficient exercise
• excessive stress / anxiety
• being male

Can lead to a myocardial infarction (heart attack) - see heart problems.

Sensations that might be indications of coronary thrombosis leading to myocardial infarction include:

• sudden sharp pain behind the sternum (breast bone)
• sudden sharp pain on the left-hand side of the chest, that might spread down the left arm
• pain radiating towards the jaw, ear, hands stomach, right arm
• constricting sensation in the throat area
• difficulty breathing
• sudden severe dizziness and/or fainting, experienced with pain.

Deep Vein Thrombosis (DVT)

See also 20. Thrombus

A thrombus is a blood clot. Thrombosis is a condition in which blood changes from a liquid into a solid state, producing a 'clot' (thrombus). Deep Vein Thrombosis (DVT) is the condition in which a blood clot forms in a deep vein in a leg (usually, but not always, a lower-leg).

Increased risk of DVT is attributed to sluggish blood flow e.g. due to

• prolonged bed rest
• pregnancy
• injury
• surgery
• travel in a small space for over 4 hours e.g. on a long flight

Other risk factors include:

• age (risk increases with age)
• obesity (health risks of obesity)
• smoking
• personal or family history of DVT
• thrombophilia (an inherited condition)

Symptoms may include:

• swelling
• pain and tenderness – may be along the vein, making it difficult to put weight on the affected leg
• reddened skin
• skin warm or hot to the touch
• mild fever

However, the above may also have other causes - seek expert advice.

Possible complications include:

• Pulmonary embolism
• Post-thrombotic syndrome
• Limb ischaemia (rare)

Haemophilia

Blood clots only very slowly (see also the blood clotting mechanism)

• Deficiency of either of two blood coagulation factors:
  • Factor VIII (antihaemophilic factor), or
  • Factor IX (Christmas factor)
• Hereditary - symptoms in males; may be 'carried' by females who can pass it to their sons without being affected themselves.

The person might experience prolonged bleeding after any injury that caused an open wound. In severe cases of haemophilia there may be spontaneous bleeding into muscles and joints.

Treatment: Bleeding in cases of haemophilia has been treated by transfusions of plasma containing the missing factor, or with concentrated preparations of Factor VIII or Factor IX obtained by freezing fresh plasma.

Haematoma

A collection or accumulation of blood outside the blood vessels, which may clot forming a swelling.

E.g. an ecchymosis, which is commonly known as a bruise, is a hematoma of the skin.

The different types haematoma, generally have different causes. E.g.

• An intracerebral haematoma may be due to a head injury.
• A perineal haematoma may occur due to bleeding from a vaginal tear or episiotomy (cut) during childbirth.

Effects & symptoms also depend on the type of haematoma. E.g.

• An intracranial haematoma might compress the brain and increase pressure within the skull
• A subdural haematoma can be life-threatening.

Haemorrhoids

Haemorrhoids (also called 'piles') are swellings containing enlarged and swollen blood vessels in or around the rectum and anus.

Risk factors - rather than direct causes - include:

• excessive body weight
• prolonged constipation e.g. due to insufficient dietary fibre
• prolonged diarrhoea
• lifting heavy objects frequently
• pregnancy � which can place increased pressure on pelvic blood vessels, though haemorrhoids often disappear after the birth
• age (above 50 years)
• family history of haemorrhoids (genetic predisposition)

Symptoms of haemorrhoids can incl.

• Bleeding (bright red blood) after passing a stool
• A pile moving down, outside of the anus (prolapse)
• a mucus discharge after passing a stool
• itchiness around the anus
• soreness and inflammation around the anus
• sensation of bowels still being full and in need of emptying

HIV/AIDS

HIV (human immunodeficiency virus) attacks the immune system, weakening ability to overcome infections and disease. AIDS is the final stage of HIV infection - when the body can no longer fight life-threatening infections.
See HIV/AIDS in the News

HIV is transmitted via bodily fluids, including blood products that have not been appropriately screened.

Examples of bodily fluids via which HIV can be transmitted:

• blood
• semen and vaginal fluids
• fluids/material inside the anus
• during birth e.g. mother to baby
• breast milk

... but not saliva alone (only if the saliva contains other fluids e.g. blood).

HIV can also be transmitted via contaminated equipment e.g. needles, syringes etc., as used to inject drugs

The human immunodeficiency virus 'takes-over' the body's own cells and uses them to produce more HIV cells. Possible symptoms of primary or acute HIV infection include:

• Fever
• Muscle soreness
• Rash
• Headache
• Sore throat
• Mouth or genital ulcers
• Swollen lymph glands
• Joint pain
• Night sweats
• Diarrhea

It is also possible to list the effects of HIV/AIDS on society (as opposed to individuals who have AIDS) and to list the side-effects of drugs used to treat HIV/AIDS.

High cholesterol

"Hypercholesterolaemia"

Hypercholesterolaemia is the presence of excessive levels of cholesterol in the blood (though there are 2 'types' of cholesterol - 'good' high-density lipoprotein HDL, and 'bad' low-density lipoprotein LDL).

Blood cholesterol levels can be graded:

• ideal: less than 5mmol/l
• too high: 5 - 6.4mmol/
• very high: 6.5 - 7.8mmol/l
• extremely high: over 7.8mmol/l

However, other considerations are also taken into account when assessing the possible health consequences of cholesterol levels.

Genetic and environmental factors affect blood cholesterol level. Possible causes of high cholesterol include:

• Food choices - dietary options
• Obesity
• Inactivity (insufficient exercise)
• Age
• Family history / genetics
• Overall health
• certain other conditions e.g. diabetes

Excessive cholesterol in the blood is not a disease per se, but can lead to the hardening and narrowing of the arteries and therefore the effects of atherosclerosis. So, possible effects of high cholesterol include:

• Angina
• Coronary heart disease
• Heart arrhythmias
• Transient ischemic attack (TIA, or "mini" stroke)
• Heart attack
• Stroke
• High blood pressure

High blood pressure (hypertension)

Blood pressure greater than

for a significant period of time.

The many possible causes include e.g.

• Unknown cause 'essential hypertension', or 'hyperpiesia'
• As a result of kidney disease, including narrowing of the renal artery (renal hypertension)
• Endocrine diseases (e.g. Cushing's disease or phaeochromocytoma)
• Disease of the arteries (e.g. contraction of the aorta), known as 'secondary hypertension', or 'symptomatic hypertension'

More general contributory factors are :

• Stress, Obesity, Age, Social Class, Smoking, Lack of exercise, Poor diet.

• Damage to arteries & veins
• Holes get blocked up by cholesterol

Hypertension is symptom-less until the symptoms of its complications develop.

These include :

• Atherosclerosis
• Heart failure
• Cerebral haemorrage
• Kidney failure

Leukaemia

Commonly described as a cancer of the blood cells, the Oxford concise Colour Medical Dictionary (1998 copy) states that the term 'leukaemia' can refer to any of a group of *malignant diseases in which bone marrow and other blood-forming organs produce increased quantities of certain types of white blood cells (leucocytes).

*malignant means that the condition e.g. tumour is tending or expected to worsen. In the context of cancer a malignant tumour is not self-limited in its growth but rather is capable of invading into adjacent tissues - possibly even spreading to distant tissues.

There are some risk factors (examples below), but most people exposed to these do not go on to develop leukaemia and many people who do have this condition have no known 'risk factors'.

• Exposure to unsafe radiation (esp. artificial ionizing radiation)
• Exposure to certain chemicals such as benzene
• Certain types of chemotherapy e.g. to treat another cancer
• Some viruses e.g. HTLV-1 & HIV
• Genetic predisposition
• Transmission from mother to child is are.

Overproduction of leucocytes that are immature or abnormal forms suppresses the production of normal white cells, red cells and platelets. This leads to increased susceptibility to infection (due to neutropenia), anaemia, and bleeding (due to thrombocytopenia).

General symptoms include

• Fever and night sweats
• Headaches
• Bruising or bleeding easily
• Bone or joint pain
• Enlarged spleen
• Swollen lymph nodes in the armpit, neck, or groin
• Frequent infections
• Tiredness / weakness
• Loss of weight
• Loss of appetite

Low blood pressure (hypotension)

Blood pressure lower than

for a significant period of time.

Can occur following:

• Excessive fluid loss (e.g. through diarrhoea, burns or vomiting)
• Severe blood loss (haemorrhage)

Other possible causes incl.

myocardial infarction (i.e. 'heart attack'), pulmonary embolism, severe infections, allergic reaction, arrhythmias, acute abdominal conditions, addisons disease, drugs

Temporary Hypotension:

• Simple faint (syncope)
• Light-headed
• Sweats
• Impaired consciousness

Severe Hypotension:

• Peripheral circulatory failure (cardiogenic shock)
• Unrecordable blood pressure
• Weak pulses
• Suppression of urine production

Hepatitis

Hepatitis is inflammation of the liver.

Hepatitis is caused by:

• viruses (several types, hence the different forms of hepatitis A, B, C. D, E)
• toxic substances or
• immunological abnormalities.

See the effects / symptoms of the specific forms (A-E) of hepatitis listed below.

Hepatitis A -

(epidemic hepatitis)

Transmission can occur via contaminated food or drinks - which could be contaminated by someone who has the diseases or by a 'carrier'. The risk is highest in areas where sanitation is poor.

Symptoms occur after an incubation period of 15-40 days and can include:

• fever / sickness
• jaundice (yellow discolouration of skin, which can last for about 3 weeks)

Serious long-term complications are unusual.

Hepatitis B -

(formerly known as serum hepatitis)

Transmission can occur by:

• infected blood or blood products
• other bodily fluids e.g. sweat
• contaminated needles e.g. hypodermic or tattooing needles
• sexual contact

Symptoms develop suddenly after 1-6 months incubation and include:

• headache
• fever
• chills
• general weakness
• jaundice

Although most patients make a gradual recovery the mortality rate is 5-20%.

Hepatitis C -

(formerly known as
non-A, non-B hepatitis)

Mode of transmission similar to that of hepatitis B (see above).

Symptoms of hepatitis C include:

• fatigue
• sore bones
• dryness of the eyes

Hepatitis D -

Hepatitis D is a defective virus that only occurs with or after infection with hepatitis B.

People who have hepatitis D tend to develop severe chronic hepatitis.

Hepatitis E -

Transmitted by infected food or drinks.

Hepatitis E can cause acute hepatitis.

Phlebitis

Inflammation in the wall of a vein, most commonly found in the legs - as a complication of varicose veins

• a complication of varicose veins

A segment of vein becomes tender and even painful. The surrounding skin feels hot and appears red. Thrombosis often develops.

Treatment: Typically involves elastic support in combination with drugs to relieve inflammation and pain..

Septicaemia

Blood poisoning

Some causes of septicaemia include:

• untreated infections of the mouth or teeth
• Infections of cuts or surgical wounds
• Burns, esp. 3rd degree burns - the larger the burn, the greater the chance of infection
• Internal injury, e.g. abdominal injury after a car accident - may involve intestinal rupture, gall bladder disease and rupture of the appendix or spleen
• Partial / missed miscarriage - if pregnancy remains stay in the uterus and become infected

Some conditions can lead to increased risk of septicaemia e.g. autoimmune disorders. Diabetes is also associated with an increased risk of septicaemia, esp. re. foot injuries

Can extend to widespread destruction of tissues due to the absorption of disease-causing bacteria or their toxins from the bloodstream.

Stress

There are two major aspects of stress:

1. Mental / emotional - sense of inability to cope with the circumstances and situations of life. See also anxiety symptoms.
2. Physical response to emotional state of anxiety incl. e.g. release into the bloodstream of certain hormones and the body's response to them.

Causes of stress are a combination of

1. life circumstances e.g. imminent exams, divorce, bereavement, loss of income, etc. and
2. how the person responds to those situations e.g. with fear, anger, denial etc. as opposed to preparation, making new plans, optimism about the future etc..

While it isn't helpful to blame anyone suffering the effects of stress, it is often possible to effect changes in attitude or lifestyle that can help to reduce adverse consequences on physical health and well-being.

The effects of stress on the circulatory system can include:

• increase in blood pressure - long-term hypertension can have serious adverse consequences
• prolonged stress can adversely affect blood flow to the extremities e.g. fingers and toes
• possible increased risk of stroke - based on research on middle-aged men in Finland

Thrombus

A blood clot.

Thrombosis is a condition in which blood changes from a liquid into a solid state, producing a 'clot' (thrombus).

Virchow's triad is a set of 3 broad categories of factors that are thought to contribute to thrombosis. They are:

• the composition of the blood - called hypercoagulability
• how the blood flows (e.g. stasis, turbulence) - called hemodynamic changes
• the quality of the wall of the blood vessel - e.g. if there is any endothelial injury / dysfunction

In general, a thrombus might develop in a blood vessel that is in a diseased state. Deep vein thrombosis (DVT) in particular is sometimes associated with inflammation. See No.7 for more about DVT.

• Thrombosis in an artery obstructs the blood flow to the tissue it supplies. Obstruction of an artery to the brain is one of the causes of a stroke. Thrombosis in an artery supplying the heart (coronary thrombosis - see above) results in a heart attack.
• Thrombosis in an vein: Deep vein thrombosis (DVT) is outlined in No.7 (above). In cases of DVT there is a risk of the thrombus becoming detached from its site of formation, carried in the blood, then getting lodged/stuck in another part of the body.

Varicose veins

Veins that are distended, lengthened and tortuous. The superficial (saphenous veins) of the legs are most commonly affected. Other sites include the oesophagus and testes.

• genetic (i.e. inherited) predisposition
• obstruction to blood flow is sometimes responsible

• Visible veins may be considered unsightly - can be a cosmetic concern