--- title: "What Is a Brain Injury?" description: "Traumatic vs non-traumatic, primary vs secondary injury, and diffuse axonal injury. A foundational guide to how brain injuries occur and evolve." lang: en json-ld: | [ { "@context": "https://schema.org", "@type": "LegalService", "@id": "https://bikebrainlaw.com/#organization", "name": "Colorado Brain Injury & Bike Crash Attorneys | Bike Brain Law", "description": "Colorado brain injury and cycling accident attorneys serving Denver, Boulder, Fort Collins and statewide. Specialized TBI representation. Free consultation. Call 303.831.1116.", "url": "https://bikebrainlaw.com", "image": "https://bikebrainlaw.com/og-image.png" }, { "@context": "https://schema.org", "@type": "BlogPosting", "@id": "https://bikebrainlaw.com/blog/what-is-a-brain-injury#blogposting", "isPartOf": { "@type": "Blog", "@id": "https://bikebrainlaw.com/blog#blog", "name": "Bike Brain Law Blog" }, "mainEntityOfPage": { "@type": "WebPage", "@id": "https://bikebrainlaw.com/blog/what-is-a-brain-injury" }, "url": "https://bikebrainlaw.com/blog/what-is-a-brain-injury", "headline": "What Is a Brain Injury?", "name": "What Is a Brain Injury?", "description": "Traumatic vs non-traumatic, primary vs secondary injury, and diffuse axonal injury. A foundational guide to how brain injuries occur and evolve.", "image": { "@type": "ImageObject", "@id": "https://bikebrainlaw.com/blog/what-is-a-brain-injury#primaryimage", "url": "https://bikebrainlaw.com/images/content/img_1113-lookout-switchbacks-all-.jpg", "contentUrl": "https://bikebrainlaw.com/images/content/img_1113-lookout-switchbacks-all-.jpg", "caption": "Switchbacks on Lookout Mountain near Golden, Colorado", "description": "Switchbacks on Lookout Mountain near Golden, Colorado", "representativeOfPage": true }, "primaryImageOfPage": { "@type": "ImageObject", "@id": "https://bikebrainlaw.com/blog/what-is-a-brain-injury#primaryimage", "url": "https://bikebrainlaw.com/images/content/img_1113-lookout-switchbacks-all-.jpg", "contentUrl": "https://bikebrainlaw.com/images/content/img_1113-lookout-switchbacks-all-.jpg", "caption": "Switchbacks on Lookout Mountain near Golden, Colorado", "description": "Switchbacks on Lookout Mountain near Golden, Colorado", "representativeOfPage": true }, "thumbnailUrl": "https://bikebrainlaw.com/images/content/img_1113-lookout-switchbacks-all-.jpg", "datePublished": "2025-12-09T15:00:00.000Z", "dateModified": "2025-12-09T15:00:00.000Z", "inLanguage": "en-US", "articleSection": "Brain Injury", "keywords": "Brain Injury, Colorado, personal injury, TBI, cycling accident", "timeRequired": "PT2M", "articleBody": "There are two types of brain injuries: (1) traumatic and (2) non-traumatic. A traumatic brain injury may also be called a head injury or if mild, a concussion. A non-traumatic brain injury is caused by something inside the body, like a stroke, infection, tumor, lack of oxygen, or exposure to a toxin like polychlorinated biphenyls (PCBs). A traumatic brain injury happens when a sufficient external force outside the body causes damage to the brain tissue or disrupts brain function. The outside force could be the head hitting or being hit by an object, an object penetrating the skull and brain, a force causing the body and head to move suddenly and the brain to move inside the skull, forces from a blast, or other forces like electrical or thermal energy. Primary and Secondary Injury There are two stages of a traumatic brain injury known as the Primary Injury and the Secondary Injury. The Primary Injury is the injury that occurs at the time of initial trauma that causes structural or functional disturbance. The Secondary Injury is what happens to the brain after the Primary Injury. Brain damage from the Primary Injury includes bleeding, bruising, swelling, cuts, tears, or the shearing of nerves. Bleeding can happen in the brain or the layers inside the skull that cover the brain. Sometimes, the bleeding is microscopic and may not show up on brain imaging like a CT scan. Brain damage can be localized to a specific area or widespread and scattered throughout the brain known as Diffuse Axonal Injury (DAI). The Secondary Injury exacerbates the initial damage and leads to further damage and dysfunction. Various mechanisms occur in the brain after the Primary Injury, which may include decreased blood or oxygen supply, inflammation, excitotoxicity, oxidative stress, and metabolic dysfunction. These secondary mechanisms lead to harmful events that can change normal brain functions and lead to cellular impairment, degeneration, and death. Secondary Injury occurs over time, from minutes to days, and the inflammatory response is believed to continue for years after injury. A brain injury is not like a broken bone. While a broken bone can be painful and have its own serious effects, scientists and doctors are still uncovering and learning about the brain and how it responds to trauma.", "commentCount": 0, "additionalProperty": [ { "@type": "PropertyValue", "name": "readingTime", "value": "2 min read", "unitText": "minutes", "unitCode": "MIN" }, { "@type": "PropertyValue", "name": "wordCount", "unitText": "words" }, { "@type": "PropertyValue", "name": "characterCount", "value": 2309, "unitText": "characters" }, { "@type": "PropertyValue", "name": "headingCount", "value": 1 }, { "@type": "PropertyValue", "name": "paragraphCount", "value": 8 }, { "@type": "PropertyValue", "name": "listCount", "value": 0 } ], "author": { "@type": "Person", "@id": "https://bikebrainlaw.com/#dan-dangelo", "name": "Attorney Dan D'Angelo", "jobTitle": "Trial Lawyer · Brain Injury Advocate · Avid Cyclist", "description": "Attorney Dan D'Angelo founded D'Angelo Law Office, P.C. in 2009 and Bike Brain Law to focus exclusively on traumatic brain injury and cycling injury cases in Colorado. An avid cyclist himself, Dan combines deep TBI science knowledge with hands-on cycling experience to build winning cases against insurance companies and corporations that put profits over safety.", "image": { "@type": "ImageObject", "url": "https://bikebrainlaw.com/images/content/20231015_dangelo_dan_square_076.jpg", "contentUrl": "https://bikebrainlaw.com/images/content/20231015_dangelo_dan_square_076.jpg", "caption": "Attorney Dan D'Angelo" }, "url": "https://bikebrainlaw.com/#about", "worksFor": { "@id": "https://bikebrainlaw.com/#organization" } }, "publisher": { "@id": "https://bikebrainlaw.com/#organization" } }, { "@context": "https://schema.org", "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "Home", "item": "https://bikebrainlaw.com" }, { "@type": "ListItem", "position": 2, "name": "Blog", "item": "https://bikebrainlaw.com/blog" }, { "@type": "ListItem", "position": 3, "name": "What Is a Brain Injury?", "item": "https://bikebrainlaw.com/blog/what-is-a-brain-injury" } ] } ] --- [![Bike Brain Law](/assets/logo-white-CuISKEAM.webp)](/)[303.831.1116](tel:3038311116) Practice Areas Practice Areas - [Brain Injury Focused brain injury representation backed by science, trial experience, and real results. ](/practice-areas/traumatic-brain-injury) - [Cycling Accidents An avid cyclist who fights for injured riders across Colorado. ](/practice-areas/cycling-accidents) - [Bicycle Product Liability Holding manufacturers accountable when defective bike parts cause injuries. ](/practice-areas/bicycle-product-liability) Resources - [Insights & Guides ](/blog) - [Case Results ](/results) - Our Process - FAQs Service Areas - [Denver](/service-areas/denver) - [Boulder](/service-areas/boulder) - [Fort Collins](/service-areas/fort-collins) - [Golden](/service-areas/golden) - [Colorado Springs](/service-areas/colorado-springs) - [Aurora](/service-areas/aurora) Featured [ ![Attorney Dan D'Angelo](/assets/dan-dangelo-headshot-DJ4GY3yR.jpg) Meet Attorney Dan D'Angelo Trial lawyer, trusted brain injury advocate, avid cyclist. Learn more ](/) Free consultation · No fee unless we win. Talk to Dan AboutTestimonials[Results](/results)FAQsContact[Insights & Guides](/blog)Free Consultation [](tel:3038311116) [All articles](/blog) [Brain Injury](/blog/brain-injury)· December 9, 2025· 2 min read # What Is a Brain Injury? Traumatic vs non-traumatic, primary vs secondary injury, and diffuse axonal injury. A foundational guide to how brain injuries occur and evolve. ![Dan D'Angelo](/images/content/20231015_dangelo_dan_square_076.jpg) By Attorney Dan D'Angelo Trial Lawyer · Brain Injury Advocate · Avid Cyclist ![Switchbacks on Lookout Mountain near Golden, Colorado](/images/content/img_1113-lookout-switchbacks-all-.jpg) There are two types of brain injuries: (1) traumatic and (2) non-traumatic. A traumatic brain injury may also be called a head injury or if mild, a concussion. A non-traumatic brain injury is caused by something inside the body, like a stroke, infection, tumor, lack of oxygen, or exposure to a toxin like polychlorinated biphenyls (PCBs). A traumatic brain injury happens when a sufficient external force outside the body causes damage to the brain tissue or disrupts brain function. The outside force could be the head hitting or being hit by an object, an object penetrating the skull and brain, a force causing the body and head to move suddenly and the brain to move inside the skull, forces from a blast, or other forces like electrical or thermal energy. ### Primary and Secondary Injury Related from Bike Brain Law - [Traumatic Brain Injury Claims How we build winning TBI cases against insurers. ](/#practice-areas) - [TBI & Injury FAQs Answers to the questions brain injury victims ask most. ](/#faqs) - [Our Case Process What to expect from consultation to settlement. ](/#process) Free, confidential case review ### Injured in a brain injury or serious accident in Colorado? Talk directly with Attorney Dan D'Angelo for a free consultation with zero obligation to find out where you stand. [Get My Free Consultation](/#contact) [303.831.1116](tel:3038311116) There are two stages of a traumatic brain injury known as the Primary Injury and the Secondary Injury. The Primary Injury is the injury that occurs at the time of initial trauma that causes structural or functional disturbance. The Secondary Injury is what happens to the brain after the Primary Injury. Brain damage from the Primary Injury includes bleeding, bruising, swelling, cuts, tears, or the shearing of nerves. Bleeding can happen in the brain or the layers inside the skull that cover the brain. Sometimes, the bleeding is microscopic and may not show up on brain imaging like a CT scan. Brain damage can be localized to a specific area or widespread and scattered throughout the brain known as Diffuse Axonal Injury (DAI). The Secondary Injury exacerbates the initial damage and leads to further damage and dysfunction. Various mechanisms occur in the brain after the Primary Injury, which may include decreased blood or oxygen supply, inflammation, excitotoxicity, oxidative stress, and metabolic dysfunction. These secondary mechanisms lead to harmful events that can change normal brain functions and lead to cellular impairment, degeneration, and death. Secondary Injury occurs over time, from minutes to days, and the inflammatory response is believed to continue for years after injury. A brain injury is not like a broken bone. While a broken bone can be painful and have its own serious effects, scientists and doctors are still uncovering and learning about the brain and how it responds to trauma. ## Have a question about your case? Attorney Dan D'Angelo offers free consultations for brain injury and cycling accident victims throughout Colorado. [Free Consultation](/#contact) [303.831.1116](tel:3038311116) ![Dan D'Angelo](/images/content/20231015_dangelo_dan_square_076.jpg) About the Author ### Attorney Dan D'Angelo Trial Lawyer · Brain Injury Advocate · Avid Cyclist Attorney Dan D'Angelo founded D'Angelo Law Office, P.C. in 2009 and Bike Brain Law to focus exclusively on traumatic brain injury and cycling injury cases in Colorado. An avid cyclist himself, Dan combines deep TBI science knowledge with hands-on cycling experience to build winning cases against insurance companies and corporations that put profits over safety. - Practicing Colorado personal injury attorney since 2009 - Focused practice in TBI and bicycle injury litigation - Multi-million dollar settlements and verdicts for injury victims - Avid road and commuter cyclist ## Related articles [ ![Brain imaging scans on a medical lightbox](/images/content/img_7090.jpg) #### Can a Denver Attorney Take My Traumatic Brain Injury Case to Trial? ](/blog/can-a-denver-attorney-take-my-tbi-case-to-trial)[ ![Racks of bicycles at a train station](https://odfyhkstsknriaebnttc.supabase.co/storage/v1/object/sign/blog-images/4aa19bbd-3cb5-4c36-a7ac-e40bf22d19ed.jpeg?token=eyJraWQiOiJzdG9yYWdlLXVybC1zaWduaW5nLWtleV81NTc3MTNiMy1mM2NiLTRjZmEtYmM3Yi0wYmQ0NmVmZjE3ZjIiLCJhbGciOiJIUzI1NiJ9.eyJ1cmwiOiJibG9nLWltYWdlcy80YWExOWJiZC0zY2I1LTRjMzYtYTdhYy1lNDBiZjIyZDE5ZWQuanBlZyIsInNjb3BlIjoiZG93bmxvYWQiLCJpYXQiOjE3ODUzNDY3NTksImV4cCI6MjEwMDcwNjc1OX0.xJyXEWuIgBqj1qmDqQQdai23W09gRBBqooyEtV3uisw) #### Why loss of consciousness is difficult to spot and why it's so important to your legal case. ](/blog/why-loss-of-consciousness-is-difficult-to-spot-and-how-to-identify-it)[ ![Treelined path with cyclist posing at the end](https://odfyhkstsknriaebnttc.supabase.co/storage/v1/object/sign/blog-images/55e622d3-709b-4210-a141-ac41b5765070.jpg?token=eyJraWQiOiJzdG9yYWdlLXVybC1zaWduaW5nLWtleV81NTc3MTNiMy1mM2NiLTRjZmEtYmM3Yi0wYmQ0NmVmZjE3ZjIiLCJhbGciOiJIUzI1NiJ9.eyJ1cmwiOiJibG9nLWltYWdlcy81NWU2MjJkMy03MDliLTQyMTAtYTE0MS1hYzQxYjU3NjUwNzAuanBnIiwic2NvcGUiOiJkb3dubG9hZCIsImlhdCI6MTc4NTM1MDA4MiwiZXhwIjoyMTAwNzEwMDgyfQ.y_WQrz9NT3BkAoSyOlpdMw9IrxR3LDOQRK0TKozc9dA) #### How long do brain injury symptoms last? ](/blog/how-long-do-brain-injury-symptoms-last) [![Bike Brain Law](/assets/logo-white-CuISKEAM.webp)](/) Colorado's dedicated brain injury and cycling accident attorney. Serving Denver and communities across Colorado. [](https://www.instagram.com/bikebrainlaw/)[](https://www.facebook.com/BikeBrainLaw/) ## Practice Areas - [Traumatic Brain Injury Claims](/practice-areas/traumatic-brain-injury) - [Cycling Accident Claims](/practice-areas/cycling-accidents) - [Bicycle Product Liability](/practice-areas/bicycle-product-liability) - Distracted Driver Injuries - Aggressive Driver Injuries - Dangerous Property Conditions - Insurance Claim Negotiation - Litigation & Trial ## Colorado Cities Served - Arvada - Aspen - [Aurora](/service-areas/aurora) - [Boulder](/service-areas/boulder) - Castle Rock - Centennial - [Colorado Springs](/service-areas/colorado-springs) - Cortez - Crested Butte - [Denver](/service-areas/denver) - Durango - [Fort Collins](/service-areas/fort-collins) - [Golden](/service-areas/golden) - Greeley - [Lakewood](/service-areas/lakewood) - Littleton - Longmont - Loveland - Pueblo - Steamboat Springs - Sterling - Thornton - Vail - Westminster ## Contact - [303.831.1116](tel:3038311116) - [info@bikebrainlaw.com](mailto:info@bikebrainlaw.com) - 3000 Lawrence St. #23 - Denver, CO 80205 Bike Brain Law is the DBA of D'Angelo Law Office, P.C. and Attorney Daniel E. D'Angelo, Esq., 3000 Lawrence Street #23, Denver, CO 80205, and is responsible for the content of this website. © 2026 Bike Brain Law. All rights reserved. [Privacy Policy](/privacy)[Terms of Use](/terms) Made with ❤️ by [HEARD](https://heardmarketing.io) [Free Consultation](/#contact)[](tel:3038311116) [Call Now](tel:3038311116)