Understanding the 2 Main Types of Stroke: What Causes Them and How They’re Treated
How the stroke occurs will affect how doctors treat it.

If you suspect someone could be having a stroke, your main concern is making sure they get help and end up safe, supported, and healthy. Knowing what specific kind of stroke they’re having may not be on your mind; however, the type of stroke matters big time to the paramedics who arrive on the scene and to doctors at the hospital who decide on a course of treatment. That information will affect everything they do to support the patient.
“A stroke is an injury to the brain,” says Carolyn Brockington, MD, neurologist at Mount Sinai Hospital. “The injury is caused by an interruption of blood flow suddenly.”
Without blood flow, the brain lacks the oxygen it needs to function and live, and brain cells become damaged or die off. This results in permanent injury to the brain that may affect personality, communication, or coordination. Learn more about what having a stroke does to your brain.
There are two main types of stroke: ischemic strokes and hemorrhagic strokes.
What Is an Ischemic Stroke?
In the United States, the majority of strokes—over 80 percent— are ischemic strokes. “Ischemia means reduction in blood flow,” says Dr. Brockington. This could be caused by a blood clot or some other blockage in the artery.
Often, these obstructions in the arteries are caused by a hardening of the arteries known as atherosclerosis, according to the American Stroke Association. This begins when fatty deposits and cholesterol build up on the inner lining of the artery, which hardens and becomes plaque over time.
If the plaque from atherosclerosis ruptures, it can form blood clots that travel through the artery. If the artery leads to the heart, it can cause a heart attack; if it leads to the brain, it can cause a stroke.
What Is a Hemorrhagic Stroke?
The less common type of stroke is hemorrhagic stroke, which means there is bleeding in the brain. This type of stroke occurs when a weak blood vessel ruptures and blood begins to pool in the brain. The accumulating blood puts pressure on the nearby brain tissue.
This rupture can occur if a blood vessels “balloons” and fills up with blood (an aneurysm) or if the blood vessels are formed abnormally (an arteriovenous malformation). It’s possible to treat these conditions before the vessel ruptures and the hemorrhagic stroke occurs.
How Does the Type of Stroke Affect Treatment?
Both stroke types have present similar symptoms of a stroke, and both types require immediate attention. Find out here why calling 911 is so critical for stroke treatment.
Despite the similarities in stroke symptoms, treatment for the two types of stroke is very different. One of the first-line treatments for ischemic stroke—but NOT hemorrhagic stroke—is tPA, which stands for “tissue plasminogen activator.” A tPA is a thrombolytic drug—throm meaning “clot” and lytic meaning “dissolve.”
“If we think that ischemic strokes are from not enough blood flow getting to the brain, we know that tPA is a very strong blood thinner that improves blood flow to the brain,” says Dr. Brockington.
However, if you’re having a hemorrhagic stroke, increasing blood flow with a blood thinner could make your condition worse. Doctors will also look at your medical history for previous bleeding, and will find out if you are on blood thinners already for another condition, such as deep vein thrombosis or atrial fibrillation.
“Since we’re not going to give a blood thinner when somebody’s bleeding in the brain [from a hemorrhagic stroke], really what we have to do is support them through the injury,” says Dr. Brockington. The goal is to limit the amount of swelling in the brain, which reduces the amount of injury to the brain cells.
To treat a hemorrhagic stroke, doctors may use medications to control blood pressure. If the patient is already on blood thinners, doctors may provide a transfusion of blood clotting agents to halt the bleeding, according to UpToDate from Wolters Kluwer.
“Time Is Brain”
Regardless of the type of stroke, fast treatment is crucial. “In stroke treatment, we say ‘time is brain,’” says Dr. Brockington. “Every moment that goes by, there are a million brain cells that die.” The faster you can begin medical treatment, the fewer cells will be damaged, and the less severe your injury will be.
Find out how to use the acronym F-A-S-T to recognize stroke to get treatment sooner.
1
00:00:00,000 --> 00:00:02,860
[MUSIC]
2
00:00:02,860 --> 00:00:04,596
A stroke is an injury to the brain, and
3
00:00:04,596 --> 00:00:07,655
the injury is caused from
an interruption of blood flow suddenly.
4
00:00:07,655 --> 00:00:12,352
[MUSIC]
5
00:00:12,352 --> 00:00:15,190
Majority of strokes
are called ischemic stroke.
6
00:00:15,190 --> 00:00:18,600
Ischemic or
ischemia means reduction in blood flow.
7
00:00:18,600 --> 00:00:20,750
So suddenly if the brain's not
getting enough blood flow,
8
00:00:20,750 --> 00:00:24,720
maybe the blood vessel is blocked,
maybe a little clot went up to the brain.
9
00:00:24,720 --> 00:00:28,490
So that's gonna cause an ischemic stroke
from an interruption of blood flow,
10
00:00:28,490 --> 00:00:30,559
and that happens about 80% of the time.
11
00:00:30,559 --> 00:00:32,570
20% of the time is hemorrhagic.
12
00:00:32,570 --> 00:00:34,220
So hemorrhage means bleeding.
13
00:00:34,220 --> 00:00:37,650
So again, if you think of a blood
vessel full of blood in the brain,
14
00:00:37,650 --> 00:00:39,600
all of the sudden that blood
vessel is gonna rupture,
15
00:00:39,600 --> 00:00:42,560
spill, and
allow blood to settle in the brain.
16
00:00:42,560 --> 00:00:44,055
The symptoms are abrupt.
17
00:00:44,055 --> 00:00:45,650
There can be weakness in one side,
18
00:00:45,650 --> 00:00:49,410
numbness on one side, problems
with speech, problems with vision,
19
00:00:49,410 --> 00:00:52,940
problems with walking, where almost
they're walking as if they're drunk.
20
00:00:52,940 --> 00:00:54,450
If those symptoms happen suddenly,
21
00:00:54,450 --> 00:00:58,740
you need to call 911 immediately in order
to go to the closest emergency room.
22
00:00:58,740 --> 00:01:01,890
Ischemic strokes are treated
differently than hemorrhagic stroke.
23
00:01:01,890 --> 00:01:06,720
We try to give a medicine called tPA,
which is essentially a thrombolytic.
24
00:01:06,720 --> 00:01:09,350
Thromb is clot, lytic, to break up.
25
00:01:09,350 --> 00:01:12,230
So if we think that ischemic
strokes are from not enough
26
00:01:12,230 --> 00:01:16,440
blood flow getting to the brain, we know
that tPA is a very strong blood thinner
27
00:01:16,440 --> 00:01:18,340
that improves blood flow to the brain.
28
00:01:18,340 --> 00:01:21,400
But we also wanna know that someone's
not having any bleeding in the brain
29
00:01:21,400 --> 00:01:23,860
because why would you give
a blood thinner in that case?
30
00:01:23,860 --> 00:01:26,660
In addition, we're gonna be very
detailed in asking the patient,
31
00:01:26,660 --> 00:01:28,460
has there been any bleeding history?
32
00:01:28,460 --> 00:01:29,740
Are they on blood thinners?
33
00:01:29,740 --> 00:01:32,340
Because that would also
change our management, and
34
00:01:32,340 --> 00:01:37,060
whether they're eligible to have a very
strong blood thinner in acute stroke.
35
00:01:37,060 --> 00:01:40,410
For hemorrhagic stroke it's different
in terms of acute treatment.
36
00:01:40,410 --> 00:01:44,140
So since we're not gonna give a blood
thinner when somebody's bleeding in
37
00:01:44,140 --> 00:01:47,670
the brain, really what we have to do
is support them through the injury.
38
00:01:47,670 --> 00:01:50,690
So there are many things that we
need to do in terms of medication,
39
00:01:50,690 --> 00:01:54,530
control of blood pressure, etc,
to try to limit the degree of swelling so
40
00:01:54,530 --> 00:01:56,330
people don't get worse.
41
00:01:56,330 --> 00:01:59,587
In stoke treatment, we say time is brain.
42
00:01:59,587 --> 00:02:03,413
And what we mean by that is
that every moment that goes by,
43
00:02:03,413 --> 00:02:06,780
there are a million brain cells that die,
right?
44
00:02:06,780 --> 00:02:08,970
And so if that continues over and
over again,
45
00:02:08,970 --> 00:02:12,790
you know that the degree of brain that's
injured is going to be considerable.
46
00:02:12,790 --> 00:02:16,401
Come in right away and
we can really try to shorten that damage,
47
00:02:16,401 --> 00:02:20,230
and therefore the disability that
someone might have after that.
48
00:02:20,230 --> 00:02:23,999
[MUSIC]
Atherosclerosis and stroke. Dallas, TX: American Stroke Association. (Accessed on January 20, 2021 at http://www.strokeassociation.org/STROKEORG/LifeAfterStroke/HealthyLivingAfterStroke/UnderstandingRiskyConditions/Atherosclerosis-and-Stroke_UCM_310426_Article.jsp#.Wwb0LJM-fVo.)
Hemorrhagic strokes (bleeds). Dallas, TX: American Stroke Association. (Accessed on January 20, 2021 at http://www.strokeassociation.org/STROKEORG/AboutStroke/TypesofStroke/HemorrhagicBleeds/Hemorrhagic-Strokes-Bleeds_UCM_310940_Article.jsp#.Wwb2hpM-fVq.)
Patient education: hemorrhagic stroke treatment (beyond the basics). Waltham, MA: UpToDate, 2020. (Accessed on January 20, 2021 at https://www.uptodate.com/contents/hemorrhagic-stroke-treatment-beyond-the-basics#H17152723.)
Types of stroke. Atlanta, GA: Centers for Disease Control and Prevention. (Accessed on January 20, 2021 at https://www.cdc.gov/stroke/types_of_stroke.htm#ischemic.)