The Pill - may cause blood clots

NEW YORK, Sep 24 (Reuters Health) -- The latest generation of birth control pills, which were introduced in the 1980s and early 1990s, may raise a woman's risk of blood clots even more than earlier oral contraceptives, according to a report from Denmark.

However, researchers caution that the increased risk is small and the evidence is still preliminary.

From 1977 to 1993, a team of researchers led by Dr. Lene Mellemkjaer, of the Danish Cancer Society, tracked hospital admissions for venous thromboembolism, a group of disorders that includes pulmonary embolism (clots in the lung), and deep venous thrombosis (most often clots in large veins in the legs).

The study authors found that for both men and women aged 15 to 49, the number of cases of venous thromboembolism was fairly steady from 1977 to 1988. In the period from 1989 to 1993, however, the men's rate did not change, but the hospitalization rate for women was more than 16% higher.

Although Mellemkjaer and colleagues were not able to determine whether women who had blood clots were taking the third generation birth control pills, the increase in hospitalizations did coincide with increasing use of the newer drugs, they report. The so-called third generation pills were used by just 0.2% of Danish women who took oral contraceptives in 1984, but that percentage increased to 17% in 1988, 40% in 1990, and 66% in 1993.

``Our study gives support to the hypothesis that third generation birth control pills increase the risk of venous thromboembolism to a larger extent than second generation birth control pills,'' Mellemkjaer told Reuters Health. However, the Danish researcher stressed that the study could not prove that the newer pills were to blame.

However, in the report, the authors note that earlier studies have also suggested that the newer contraceptives increase the risk of blood clots more than second generation birth control pills. Most birth control pills contain either a combination of the hormones estrogen and progestogen or progestogen alone. According to Mellemkjaer, the main difference between second and third generation birth control pills is in the level of progestogen.

``The increased risk of venous thrombosis with third generation pills is real and measurable, but it is also small in absolute terms, although greatest in women starting the Pill,'' Dr. Paul A. O'Brien, of the Parkside Health NHS Trust in London, UK, writes in an accompanying editorial. He states that second generation birth control pills should be ``the first choice.''

However, some women may be willing to accept the small additional risk of blood clots in exchange for the potential benefits of the third generation pills, such as reduced acne, according to O'Brien.

``It is not that third generation contraceptives are unsafe -- it is just that we have something safer,'' he concludes.

SOURCE: British Medical Journal (1999): 319, 795-796, 820-821.

Alternative names: aneurysm, cerebral


A disorder that involves localized widening of one or more blood vessel(s) in the brain.

Causes, incidence, and risk factors

Aneurysms in the brain occur when there is a weakened area in the wall of a blood vessel. They may occur as a congenital defect or may develop later in life.

A saccular aneurysm (berry aneurysm) is usually small in size. The aneurysm resembles a sack of blood attached to one side of the blood vessel by a narrow neck. These are more common in adults. Multiple berry aneurysms are not unusual. They occur in any part of the brain but are most often seen in the large arteries at the base of the brain. Berry aneurysm is also associated with polycystic kidney disease and coarctation of the aorta. Rarely, berry aneurysm can run in families.

Other types of cerebral aneurysm may involve widening (dilatation) of the entire circumference of the blood vessel in an area, or may appear as a ballooning out of part of a blood vessel. These types of aneurysms can occur in any part of the brain.

Symptoms usually do not appear until complications develop. Bleeding is the most common cause of symptoms, with subarachnoid hemorrhage the usual type of bleed. Weakness, numbness, or other loss of nerve function (neurological deficits) may occur because of pressure from the aneurysm on adjacent brain tissue or because of reduced blood flow caused by a spasm of other blood vessels near a ruptured aneurysm.

It is estimated that 5% of the population has some type of aneurysm. However, the incidence of ruptured aneurysm is approximately 4 out of 100,000 people per year.


There is no known way to prevent formation of a cerebral aneurysm. If discovered in time, unruptured aneurysms can be treated before causing problems.


Symptoms of a bleed may include:

     sudden occurrence of a headache (severe or described as "the worst in patient's experience")

     headaches with nausea or vomiting

     stiff neck (occasionally)

     muscle weakness, difficulty moving any part of the body

     numbness or decreased sensation in any part of the body

     vision changes

     eye lid drooping

     changes in mental status, the person may be lethargic, sleepy, or stuporous


     slow, sluggish, lethargic movement

     speech impairment

     irritability or poor temper control

Note: Cerebral aneurysms have no symptoms until complications such as bleeding occur.

Signs and Tests

There may be signs of increased pressure within the brain (intracranial pressure) including swelling of the optic nerve (papilledema) that is shown on eye examination.

Cerebral aneurysm is usually diagnosed by tests to determine the cause of bleeding within the brain.

A CT scan of the head indicates bleeding and occasionally locates the aneurysm.

A CSF (cerebrospinal fluid) examination may confirm bleeding when CT scan is non-diagnostic.

An MRI of the head may be an alternative to a CT scan, but is not as sensitive to bleeding within the brain (subarachnoid bleeding).

Cerebral angiography pinpoints the location of the aneurysm(s).

EEG (electroencephalogram) may be performed if seizures occur.


Because symptoms often do not appear until bleeding occurs, cerebral aneurysm may be an emergency condition when it is discovered. The goal of treatment is to control symptoms and prevent further bleeding. Surgery is the primary treatment for cerebral aneurysm. The base of the aneurysm is closed off with clamps, sutures, or other methods that prevent blood flow through the aneurysm. If surgery is not feasible because of the location or size of the aneurysm or the condition of the person, medical treatment is similar to treatment for subarachnoid hemorrhage. This may include restricting activity (often complete bedrest is advised), treating symptoms such as headache, and prescribing preventive (prophylactic) use of antiseizure medications.

Expectations (prognosis)

The outcome varies. A cerebral aneurysm that does not rupture may not cause any symptoms. However, about 25% of ruptured cerebral aneurysms are fatal within 24 hours. Another 25% are fatal within about 3 months. Of the remaining people with ruptured cerebral aneurysm, more than one-half will have some sort of permanent disability.


                       subarachnoid hemorrhage



                       paralysis of any part of the body

                       permanent loss of sensation of any part of the body

                       other neurologic deficits (such as vision changes, loss of speech ability)

                       communicating hydrocephalus

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A birth defect in which the major artery from the heart (the aorta) is narrowed somewhere along its length; most commonly the narrowing is just past the point where the aorta and the subclavian artery come together.

Causes, incidence, and risk factors

Coarctation is a birth defect (congenital disorder) in which a portion of the aorta is narrowed, resulting in low blood pressure and low blood flow past the defect and high blood pressure on the side that is closer to the heart (proximal to the defect). Most commonly, coarctation is located so that there is high blood pressure in the upper body and arms and low blood pressure in the lower body and legs.

There is an increased risk for aortic coarctation in some genetic conditions such as Turner's syndrome. It also occurs more often in boys than in girls. Symptoms from coarctation may not develop until adolescence, but can be present in infants depending on the severity of blood flow restriction. The symptoms include localized hypertension (high blood pressure in only certain parts of the body), cold feet or legs, decreased exercise performance, and heart failure. The pulse, normally felt in the groin (femoral pulse), is typically absent when a coarctation is present.

The disorder occurs in approximately 1 out of 10,000 people. It is usually diagnosed in children or adults less than 40 years old.


There is no known way to prevent this disorder. Awareness of risk may make early diagnosis and treatment possible.



                       pounding headache


                       nosebleed - symptom

                       leg cramps with exercise

                       absent or diminished pulses in the arteries of the groin (femoral pulses)

                       cold legs or feet


Note: There may be no symptoms.

Signs and Tests

An examination reveals high blood pressure in the arms, with significant blood pressure difference between arms and legs. The femoral (groin) pulse is weaker than the carotid (neck) pulse, or the femoral pulse may be absent. Listening to the heart through a stethoscope reveals a murmur that is harsh and heard in the back. There may be signs of left-sided heart failure (especially in infants) or signs of aortic regurgitation.

Coarctation os often discovered during a newborn infant's first examination or during a well baby exam. The health care provider will detect that the femoral pulses are absent or very weak. This is an important part of the examination as there may not be any other symptoms or findings until the child is older.

Coarctation of the aorta may be confirmed by:

                       coronary angiography, looking at the aorta

                       chest CT

                       MRI of the chest


                       Doppler ultrasound of the aorta

                       X-ray of the chest (may also show abnormal ribs or "notching" of ribs caused by enlargement of the rib arteries)

                       ECG that indicates left ventricle enlargement

                       cardiac catheterization


Surgery is usually advised. Occasionally, balloon angioplasty (using a similar technique to that used to open the coronary arteries, but performed on the aorta) may be an alternative to surgical repair. With surgery, the narrowed segment of the aorta is removed then repaired by anastomosis (placing the two free ends of the aorta back together) if the gap is small, or the gap may be bridged with a Dacron graft (a synthetic material used to fill larger gaps).

Expectations (prognosis)

Coarctation of the aorta is curable with surgery, and rapid improvement of symptoms can be expected after the repair. There is an earlier incidence of cardiovascular death among people with aortic repair than among the general public; however, repair leads to a marked increase in longevity over those do not have the repair made. Early surgical intervention (before 10 years old) may improve these statistics. Today, diagnosis of a coarctation and the subsequent repair typically occur during infancy. Uncorrected, coarctation usually causes death before the person is 40 years old.


                       aortic aneurysm

                       aortic dissection

                       aortic rupture

                       severe hypertension


                       intracerebral hemorrhage


                       heart failure

                       premature development of coronary artery disease (CAD)

Alternative names

aneurysm - aortic


An abnormal widening of the abdominal portion of the aorta (the major artery from the heart).

Causes, incidence, and risk factors

Abdominal aortic aneurysm involves a widening, stretching, or ballooning of the aorta. The exact cause is unknown, but risks include atherosclerosis and hypertension. Some causes of an abdominal aortic aneurysm are injury, infection, or congenital weakening of the connective tissue component of the artery wall.

Abdominal aortic aneurysm can affect anybody, but it is most often seen in men 40 to 70 years old. A common complication is ruptured aortic aneurysm. This is a medical emergency where the aneurysm breaks open, resulting in profuse bleeding. Ruptured aneurysm occurs in approximately 5 out of 10,000 people. Aortic dissectionoccurs when the lining of the artery tears and blood leaks into the wall of the artery. An aneurysm that dissects is at even greater risk of rupture. In children, abdominal aortic aneurysm can result from blunt abdominal injury or from Marfan's syndrome.


Avoid blunt trauma to the abdomen, atherosclerosis, and hypertension.


                       abdomen hernia or mass, midline, pulsating (rhythmic throbbing), with tenderness to touch

                       pulsating sensation in the abdomen

                       pain in the abdomen

                       severe, sudden, persistent or constant

                       not colicky or spasmodic

                       may radiate to groin, buttocks, or legs

                       pain may begin suddenly

                       abdominal rigidity

                       pain in the lower back

                       severe, sudden, persistent, may radiate


                       rapid pulse

                       dry skin/mouth

                       excessive thirst


                       nausea & vomiting

                       lightheadedness occurs with upright posture

                       fainting occurs with upright posture

                       sweating, excessive

                       skin, clammy

                       fatigue (tiredness or weariness) developing recently

                       heartbeat sensations

                       rapid heart rate(tachycardia) when rising to standing position

                       impaired ability to concentrate


                       abdominal mass

Note: Aneurysms may develop slowly over many years and often have no symptoms. If the aneurysm expands rapidly, tears open (ruptured aneurysm), or blood leaks along the wall of the vessel (aortic dissection), the above symptoms may develop suddenly.

Signs and Tests

Listening to the abdomen with a stethoscope (auscultation) shows a "blowing" murmur over the aorta or a "whooshing" sound (bruit). Physical examination of the abdomen is performed. If a rupture is suspected, physical examination for signs of blood loss (hypovolemia) and an evaluation of lower extremity pulses and circulation are performed.

Abdominal aortic aneurysm may show on these tests:

                       abdominal X-ray

                       abdominal ultrasound

                       MRI of abdomen

                       CT scan-abdominal

                       angiography of aorta

                       A CBC may indicate loss of blood.


If the aneurysm is small and there are no symptoms (for example, if the aneurysm is found during a routine physical examination), periodic evaluation to watch for changes may be recommended.

Symptomatic aneurysms may require treatment to prevent complications. Antihypertensive medications may be prescribed to reduce blood pressure. Other medications may include analgesics to relieve pain.

Surgical repair or replacement of the section of aorta is often recommended. The goal of treatment is timely surgical intervention before complications develop.

The risk of complications increases as the size of the aneurysm increases. Because surgery for abdominal aortic aneurysm is risky, the surgeon may wait for the aneurysm to expand to a certain size before operating (that is, when the risk of complications exceeds the risk of surgery).

Expectations (prognosis)

The probable outcome is good when an aneurysm is monitored carefully and if surgical repair is performed before the aorta ruptures. Aortic rupture is life threatening. Less than 50% of all people with a ruptured abdominal aortic aneurysm survive.


                       aortic rupture

                       bleeding from the aorta

                       hypovolemic shock

                       arterial embolism

                       insufficient circulation past the aneurysm

                       irreversible damage to the kidneys (kidney failure)

                       myocardial infarction


                       aortic dissection

Alternative names

aortic aneurysm (dissecting)


A condition in which there is bleeding into and along the wall of the aorta (the major artery from the heart); this condition may also involve abnormal widening or ballooning of the aorta (aneurysm).

Causes, incidence, and risk factors

Aortic dissection involves bleeding into and along the wall of the aorta (the major artery from the heart), most often because of a tear or damage to the inner wall of the artery. This usually occurs in the thoracic (chest) portion of the aorta but may occur in the abdominal portion also.

The exact cause is unknown, but risks include atherosclerosis and hypertension. Traumatic injury is a major cause of aortic dissection, especially blunt trauma to the chest as with the steering wheel of a car during an accident. Aortic dissection may also be associated with other injury, infection, congenital weakness of the aorta, collagen disorders such as Marfan's syndrome, pseudoxanthoma elastoma, Ehlers-Danlos syndrome, relapsing polychondritis, or abdominal aortic aneurysm. Pregnancy, valve disorders (including aortic insufficiency), and coarctation of the aorta may also be associated with aortic dissection.

Aortic dissection occurs in approximately 2 out of 10,000 people. It can affect anybody, but it is most often seen in men 40 to 70 years old.


Adequate treatment and control of atherosclerosis and hypertension may reduce risk. Use safety precautions to reduce the risk of injury. Many cases are not preventable.


                       chest pain

                       sudden, severe

                       sharp, stabbing, tearing, or ripping

                       located below the sternum, under the shoulder blades, or in the back

                       pain may radiate to shoulder, neck, arm, jaw, abdomen, hips

                       location of pain may change

                       changes in thought ability, concentration (confusion, disorientation)

                       decreased movement, any location

                       decreased sensation, any location



                       rapid pulse (heart rate)

                       profuse sweating

                       dry skin/mouth, thirst

                       nausea, vomiting

                       dizziness, fainting

                       shortness of breath (dyspnea)

                       difficulty breathing when flat (orthopnea)

                       difficulty breathing at night (paroxysmal nocturnal dyspnea)

Note: Symptoms may begin suddenly.

Additional symptoms that may be associated with this disease:

                       yawning, excessive

                       skin, clammy

                       pulse, weak or absent


                       blood pressure, high

Signs and Tests

Listening with a stethoscope (auscultation) at the chest and abdomen may reveal a "blowing" murmur over the aorta, a heart murmur, or other abnormality. There may be decreased (weak) pulses in the upper extremities. There may be signs of tamponade or hypovolemia, or signs resembling acute MI. There may be signs of shock but with normal blood pressure.

Aortic dissection or aortic aneurysm may be revealed on:

                       an aortic angiography

                       a chest MRI or CT scan of chest

                       an echocardiography

                       a chest X-ray (may show mediastinal widening)

                       a Doppler ultrasonography (occasionally performed)

                       ECG may show signs of cardiac tamponade.

                       CBC is performed to evaluate blood loss.


The goal of treatment is prevention of complications. Hospitalization is usually required.

Antihypertensives may be prescribed to reduce blood pressure. These may be given through a vein (intravenous). Analgesics may be needed for pain. Cardiac medications such as beta-blockers may reduce some of the symptoms.

Surgical repair or replacement of the section of aorta is curative.

Expectations (prognosis)

Aortic dissection may be life threatening. The disorder is curable with surgical repair if it is performed before aortic rupture. Less than half of the patients with ruptured aorta survive.


                       bleeding from the aorta

                       aortic rupture causing rapid blood loss, shock, death

                       clot formation

                       insufficient circulation past the area of the dissection

                       irreversible kidney failure


                       myocardial infarction (tissue death)

                       cardiac tamponade