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Published on: Apr 30, 2020
3 minute read
By: Dr Rajan Choudhary

COVID AND CLOTTING: A BRIEF LOOK

At the Mount Sinai hospital, a case series of five patients have been put together, ready to be published in the New England Journal of Medicine. It details patients aged 33, 37, 39, 44, and 49 who all began to experience a sudden onset of symptoms including slurred speech, confusion, drooping on one side of the face, and feeling dead in one arm. At the time of writing one has sadly died, two remain hospitalized and one is in rehab. Only the youngest is able to speak. All of them were found to be COVID positive.

This drastic case series highlights a growing problem of strokes and clotting disorders in COVID patients, one noted by medics across the world. This blog looks at whether this is a common occurrence and what may be causing it.

Before reading this blog it will be helpful to read our previous blog on why and how blood clots.

THE START

In mid-February Tang et al published a paper noting that patients with abnormal clotting parameters were associated with a poorer prognosis. In their study, 11% of their patients died, but out of these patients, 71% had these abnormal parameters, compared to just 0.6% of survivors. The patients who died also demonstrated DIC (disseminated intravascular coagulation), a condition in which clotting is triggered in the patients' blood across the body, not just at the site of injury.

There is one major issue with this study. In most European hospitals patients receive anticoagulant medications on a daily basis. This is because lying in a hospital bed when ill can promote the formation of clots in your legs. Most hospitals in China do not provide this anticoagulation, but even then the incidence of clotting is remarkably high.

After this, the evidence begins piling up. 9th April, Cui et al found 25% of patients with severe COVID had clots in their legs, of which just under half died. Looking at a specific clotting parameter (D-DIMER) was remarkably accurate at predicting high-risk patients.

Italian doctors found in 16 patients in critical care with severe Acute Respiratory Distress Syndrome (a severe inflammatory condition caused by COVID) also had deranged clotting parameters.

French studies had found these sickest patients often had large clots in their lungs, blocking blood flow in the lung and causing severe issues in keeping the patient's blood well oxygenated.

Some studies showed even patients hooked up to artificial lungs (known as ECMO) were not safe from the problems caused by excessive clotting.

WHY?

So why is this occurring? As with everything in medicine, the answer is complicated and usually multifactorial. So we will simplify it.

We must look at the platelets in our blood. These fragmented cells have an important role in triggering the clotting cascade and creating a clot. During an infection white blood cells (important immune cells responsible for finding and destroying invading organisms) release many chemical signals around an infection site. This triggers platelets, the formation of small protein meshes that can literally net the viral particles in the blood.

But it looks like they have an anti-viral role as well. Researchers have found specialist receptors on platelets that recognize viruses in the blood, leading to the release of specialist anti-viral molecules that target and destroy the viruses. This is an interesting finding because it is white blood cells that are known to destroy invading organisms.

So how does it go wrong? In severe infections, there is a very large viral load, and this can cause an excessive response. Too many white blood cells release too many chemical signals, causing too many platelets to activate. The same thing can occur with the virus directly activating too many platelets at once. This results in clots forming in the blood throughout the body, including the lung and the brain. It is another instance of the body falling victim to its own protective mechanism.

A second problem is that as these platelets are activated, they and the clotting proteins in the patient’s blood are “used up”. This is dangerous, because without these platelets and clotting proteins the body is unable to stop any bleeding sites. Profuse bleeding can occur from small injuries, further complicating the treatment of the patient.

So what can be done?

Hospitals have already started looking at giving patients with severe COVID anticoagulation therapy. And it seems in patients with deranged clotting, giving anticoagulation therapy can lower mortality. The International Society on Thrombosis and Haemostasis (Clotting) has recommended that patients with severe COVID receive high dose anticoagulation medication to thin their blood, because these patients are at such high risk of clots. This regime will be used for hospital patients and those in critical care.

And what about for the everyday public? Should we be worried? So far the data suggests this is only happening in people suffering from severe symptoms of COVID. But the incident in New York certainly raises some questions, and it will be interesting to read their report in NEMJ. Should you panic and start taking anti-coagulant medication at home? Definitely not. But what you should do is be educated in the symptoms of common diseases caused by clots. Diseases such as strokes and DVTs.

STROKE

Remember, act F.A.S.T

Facial Droop on one side
Arm or hand on one side feels numb or weak with reduced power (same in one leg)
Slurred speech making it difficult to understand
Time to phone an ambulance

Other symptoms can include sudden loss in balance, sudden loss in vision in one eye, problems swallowing, and more.

DVT

Look out for a swollen, painful calf on one side that is hot to touch.

PULMONARY EMBOLISM

If you have a swollen, painful calf and are also having trouble breathing, with some sharp stabbing pain in your chest, contact the emergency services as soon as possible.

Dr Rajan Choudhary, UK, Chief Product Officer, Second Medic Inc

www.secondmedic.com

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Stroke Warning Signs for Indians Over 40: Early Detection Can Save Lives

Introduction

Stroke is a major health issue in India — both as a cause of death and lifelong disability. For people over 40, the risk climbs sharply. The earlier a stroke is recognized and treated, the better the chances of recovery. In this post, we’ll look at the warning signs of stroke especially relevant in Indians over 40, backed by real survey data, the risk factors common in India, what to do, and how to act fast. Understanding these can help you or your loved ones catch a stroke early and reduce damage.

How Big Is the Problem in India, Especially After 40

According to a 2024 study using Global Burden of Disease data, stroke incidence in India has increased from 76 per 100,000 people in 1990 to ??88 per 100,000 in 2021 for all ages.
Stroke incidence and burden are especially high among people aged 50-69 and over 70.
Another study in North India showed that a large number of adults over 45 lacked awareness about warning signs of stroke: nearly 46% didn’t know warning signs.
Among hypertensive patients (~mean age 54) from Western Rajasthan, about 75% recognized at least one stroke symptom like slurred speech or body-weakness, but 25-30% still lacked awareness.

These figures show that though awareness is improving, there is a significant gap in recognition of warning signs among people over 40 — a high-risk group.

Warning Signs of Stroke (What to Look Out For)

In Indians over 40, common symptoms are similar globally, but here are those particularly reported in Indian surveys:

Sudden Weakness or Numbness on One Side
Many people identified “paralysis of one side of the body” or weakness in an arm or leg. In a Tamil Nadu hospital-based survey, 56% of respondents recognized this symptom.
Facial Droop or Deviation
One side of face droops or mouth slants. In the same survey, ~20% noted deviation of the mouth.
Speech Problems
Slurring, garbled speech, or trouble understanding what others are saying. ~16% in that survey recognized speech impairment.
Vision Disturbance
Sudden trouble with sight in one or both eyes (blurring, loss of vision). Awareness of this is lower: about 53% recognized vision disturbances in a Kerala survey.
Loss of Balance, Dizziness, Severe Headache
Sudden loss of balance or coordination, dizziness, confusion, or sudden, severe headache are also warning signs. Surveys show these are less well recognized compared to motor or speech symptoms but still important.

Risk Factors: What Makes Stroke More Likely After Age 40

Understanding risk helps prevention:

Hypertension (High Blood Pressure) — arguably the biggest factor. Many over-40 Indians have undiagnosed or uncontrolled high BP.
Diabetes Mellitus — often co-exists; increases damage to blood vessels.
Dyslipidemia (High Cholesterol / Lipids)
Smoking & Tobacco Use — cigarettes, chewing tobacco.
Alcohol Use
Obesity / Sedentary Lifestyle
Dietary Risks — high sodium, low fruits/vegetables.
Heart Conditions — atrial fibrillation, prior heart disease.
Other — age itself, stress, sometimes air pollution.

Awareness & Knowledge: What Indian Surveys Reveal

In the Rajasthan survey among hypertensive patients (mean age ~54), around 75-80% knew at least one major warning sign (one?side weakness, speech or vision issues), but 25-30% were unaware.
In a community survey in Kerala, 94.2% identified facial weakness, 86.6% speech disturbances, 84.5% limb weakness. But only ~53% recognized vision issues as a symptom.
In a North Indian telephone survey, nearly half the participants (?46%) did not know warning signs.

So even in literate, more urban or health-aware areas, a non-trivial proportion of people over 40 are not fully aware.

Why Early Recognition Matters

Treatments like thrombolysis (clot-busting medications) are time sensitive — often must be given within a few hours (“golden hour”). Delays drastically reduce benefit.
Early hospital arrival, correct diagnosis, and starting therapy quickly can reduce severity, prevent permanent disability, reduce mortality.
Preventing recurrence: once someone has had a stroke (or mini-stroke), risk of further strokes increases. Early intervention (lifestyle, medicines) matters.

What to Do If You or Someone Over 40 Notices These Signs

Don’t Delay — If sudden facial droop, weakness on one side, speech issues, vision trouble, or sudden severe headache occurs, seek emergency medical help immediately (call ambulance / go to hospital).
Note the Time — When symptoms started. Critical for treatment options.
Diagnostic Tests may include CT/MRI brain, ECG, carotid imaging, labs (blood sugar, lipids etc.).
Medical Management — Control high blood pressure, diabetes, cholesterol; anticoagulants if needed; lifestyle changes.
Rehabilitation — Speech therapy, physiotherapy, occupational therapy if deficits remain.

Real Numbers: What Are the Outcomes / Burden

Adjusted stroke prevalence in India is estimated between 84 and 262 strokes per 100,000 in rural areas, and 334-424 per 100,000 in urban areas depending on the region.
Among those aged 55+, stroke rates jump — e.g., in Trivandrum, rate is ~7.1 per 1,000 people per year for 55+, rising to 13.3 per 1,000 for those aged 75+.
The chance of having a stroke after 55 is roughly 1 in 5 for women and 1 in 6 for men in certain studies, though this includes all adults over 55.

Challenges in India

Delays in recognising signs and reaching hospital. Many people don’t know less obvious symptoms.
Low awareness of treatments and golden period for therapy. Surveys show only a small fraction know about clot lysis or emergency window.
Access issues: hospitals with stroke care, imaging etc. may be far. Costs, transport, awareness all barriers.
Comorbidities often unmanaged (hypertension, diabetes).

Prevention: What Indians Over 40 Can Do Now

Regular health checkups: Monitor blood pressure, blood sugar, cholesterol.
Lifestyle changes: Healthy diet (low salt, more fruits/veg), active lifestyle, avoid tobacco, limit alcohol.
Stay alert to symptoms: Educate self / family about warning signs.
Emergency planning: Know nearest hospital that handles stroke, keep travel / transport options ready.
Medication adherence: If prescribed (for BP, diabetes, heart conditions), don’t skip.

Conclusion & Call to Action

Stroke warning signs for Indians over 40 are often clear—but awareness is still incomplete. Because stroke risk increases with age, recognizing the early warning signs like sudden weakness, facial droop, speech trouble, vision disturbance, and balance issues can make all the difference.

If you or someone over 40 feels any of these, act fast. Time matters. Go to the hospital immediately.

CTA: If you’re over 40, schedule a stroke risk assessment today — check your blood pressure, diabetes, cholesterol, and get informed about warning signs. A simple health check can save your life or someone you care about.

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