Many people use grief and sadness interchangeably, but they are two very different things.

Grief can manifest itself differently for different people based on a number of factors. When it comes to the loss of a loved one or pet, the severity of grief is often associated with how close the grieving person was to the deceased.

After we lose someone, especially if they are very close to us, we experience more than just not having them physically around anymore. The loss can disrupt many aspects of our life that were attached to that person, like things we did together or things that remind us of them.

According to Christina Rasmussen, the founder of Second Firsts, an organization that helps people create a pathway back to life after loss, there are three phases to healthy recovery after loss:

• Our loss disrupts our normal routines and we exit our old life.
• We begin living in a gap between our old life and the life we have yet to live.
• We begin to experiment with and live our new life.

This is why when we grieve for someone that we weren’t very close to, or that we didn’t have very many memories of, we don’t grieve in quite the same way as someone who loses a parent, a child, a spouse, or a best friend.

Physical Effects of Grief

Because of the disruptive nature of losing someone you love, you experience more than just sadness or loneliness. The trauma of loss causes your brain to sense the world around you as unsafe, uncertain, and confusing because it has lost a lot of familiarity.

Because your brain thinks that the world you live in is no longer safe, it triggers the amygdalae, which are almond-shaped masses of gray matter that control your fight-or-flight response. In response, the amygdalae secrete stress hormones like adrenaline, which can have an effect on your mental wellbeing as well as your immune system.

It is because of these stress hormones that grief is different than ordinary sadness. Adrenaline, as well as the stress hormones epinephrine and cortisol, have a real, tangible effect on our bodies, including:

Grief also manifests itself after more than just a death — it can occur after other major losses like a divorce, a breakup, a house fire, a natural disaster, or a serious injury. This is because you grieve for more than just the loss of a person or pet — you grieve for a life you can likely never return to.

Your Grief is Normal

What’s important to realize is that grief, though it varies between people and situations, is completely normal. It’s also important to know that grieving is a highly individual experience, and how you grieve depends on your personality, your coping style, your life experience, your faith, and much more.

Though many believe they will go through the five stages of grief, also known as the Kübler-Ross model, not everyone goes through each stage in order to heal. The five stages — denial, anger, bargaining, depression, and acceptance — are merely observations that psychiatrist Elisabeth Kübler-Ross made while studying the feelings of patients facing terminal illness.

If you or someone you love is currently grieving, here’s what you should keep in mind:

• Grief is completely normal, and it happens to most people in some way.
• Everybody’s grief is different, and what works for you may not work for someone else.
• Grief is more than just sadness or loneliness.
• It’s important to allow yourself to grieve.
• Taking extra care of your health is a good idea to offset the effects of stress hormones.

If you need some inspiration for ways to cope with your grief, check out our tips for how you can grieve or help a child grieve.