science

Hematoma

Hematoma is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Hematoma rather than just read about it. In short: A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillaries. A hematoma is benign and is initially in liquid form spread among the tissues including in sacs between tissues where it may coagulate and solidify before blood is reabsorbed into blood ve…

Key takeaways

Hematoma belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Hematoma to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Hematoma from memory before moving on to harder problems.

Reference excerpt

A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillaries. A hematoma is benign and is initially in liquid form spread among the tissues including in sacs between tissues where it may coagulate and solidify before blood is reabsorbed into blood vessels. An ecchymosis is a hematoma of the skin larger than 10 mm. They may occur among and or within many areas such as skin and other organs, connective tissues, bone, joints and muscle. A collection of blood (or even a hemorrhage) may be aggravated by anticoagulant medication (blood thinner). Blood seepage and collection of blood may occur if heparin is given via an intramuscular route; to avoid this, heparin must be given intravenously or subcutaneously.

Signs and symptoms

Some hematomas are visible under the surface of the skin (commonly called bruises) or possibly felt as masses or lumps. Lumps may be caused by the limitation of the blood to a sac, subcutaneous or intramuscular tissue space isolated by fascial planes. This is an anatomical feature that helps prevent injuries from causing massive blood loss. In most cases a hematoma as a sac of blood eventually dissolves; however, in some cases it may continue to grow due to blood seepage or show no change. If the sac of blood does not disappear, then it may need to be surgically cleaned out or repaired. The slow process of reabsorption of hematomas can allow the broken down blood cells and hemoglobin pigment to move in the connective tissue. For example, a patient who injures the base of their thumb might cause a hematoma, which will slowly move all through their finger within a week. Gravity is the main determinant of this process. Hematomas on articulations can reduce mobility of a member and present roughly the same symptoms as a fracture. In most cases, movement and exercise of the affected muscle is the best way to introduce the collection back into the bloodstream.

Classification

Types

Subdermal hematoma (under the skin) Intramuscular hematoma (inside muscle tissue) Skull/brain: Subgaleal hematoma – between the galea aponeurosis and periosteum Cephalohematoma – between the periosteum and skull. Commonly caused by vacuum delivery and vertex delivery. Epidural hematoma – between the skull and dura mater Subdural hematoma – between the dura mater and arachnoid mater Subarachnoid hematoma – between the arachnoid mater and pia mater (the subarachnoid space) Othematoma – between the skin and the layers of cartilage of the ear Breast hematoma (breast) Perichondral hematoma (ear) Perianal hematoma (anus) Subungual hematoma (nail) Rectus sheath hematoma Genital hematoma

Degrees Petechiae – small pinpoint hematomas less than 3 mm in diameter; Purpura (purple) – a bruise about 3-10 mm in diameter, generally round in shape; Ecchymosis – subcutaneous extravasation of blood in a thin layer under the skin, i.e. bruising, over 1 cm in diameter.

Etymology The English word "haematoma" came into use in 1826. The word derives from the Greek αἷμα haima "blood" and -ωμα -oma, a suffix forming nouns indicating a mass or tumor.

See also Metanephric dysplastic hematoma of the sacral region Welts

References

External links

Media related to Hematomas at Wikimedia Commons

Illustrations

Worked examples

Example 1 — a first encounter with Hematoma

Start with the simplest possible case. Write down what Hematoma claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Hematoma before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Hematoma ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Hematoma

In research: Hematoma appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Hematoma in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Hematoma is common in secondary-school and first-year university syllabi. It links to neighbouring topics Gross pathology, so understanding it makes those chapters shorter.
In everyday life: Look for Hematoma outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Hematoma in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Hematoma means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Hematoma out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Hematoma in simple terms?

Why does Hematoma matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Hematoma?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Hematoma.