Physical Symptoms of Depression
Depression manifests mostly in mental and emotional well-being. But knowing any presence of physical symptoms can give a signal when a depressive period is about to begin or already experiencing.

I am not an expert but I will share with you the things I observed and experienced from what my dear Enzo went through. These are all hindsight. I hope this will reach mothers like me clueless and confused with the changes in our children's behavior. I myself have realized it just now when I am going through depression myself.
Depression is real... and it really hurts and is exhausting!! We often associate this mental illness with extreme sadness, a sudden burst of anger, constant detachment, and a feeling of hopelessness but before we jumped to conclusion that our child is just giving us hard time, watch out for these physical changes. These symptoms may look common especially to teenagers. Depression is deceitful. It is unnoticeable. It creeps up slowly until a big black cloud forms overhead its victim.
1. Fatigue
Enzo was extremely an active boy. He was cheerful in helping me with household chores. He never miss any assigned task. At school and community, he's always the first one to raise his hand when asked for a volunteer. Last year, during the quarantine at home, I noticed he started to spend a lot of time idle or onscreen. I thought he was just too lazy or too tired because of excessive screen time.
But I was wrong big time! Depression eats up all his energy. He was unhappy doing the things that brings him joy before. There's a huge effort and pressure on him. He was always tired and irritable. He said he can't keep up with all the responsibilities on his hand. He lost his interest and became detached. Eventually, he quit his church activities (YFC/AS) and violin lesson.
2. Bad Sleeping Habit
I thought it's just normal for teenagers to sleep late at night. Because he spent a lot of time on his cellphone, I held the gadget culprit of my son's bad sleeping pattern. I tried to shut off all the destructive reasons I could think of just to make him get enough sleep. At bedtime, I used to confiscate my boys' cellphones, turned off the wifi, and diffused essential oils to help them sleep but I will wake up after midnight surprised to see my Enzo is still wide awake, singing to himself. He said; he can't sleep and not to worry because he will fall asleep eventually. I let it pass and thought he may have insomnia like his dad so we occasionally gave him melatonin to help him sleep.
3. Loss of appetite and Stomach discomfort
Enzo was not a picky eater. He glowed at the sight of food. He was easy to please with food. Though he was not fond of cooked seafood because of the need to remove its shell or the fishbone, he was more into ready-to-eat sushi, tempura, and kilawin (raw, fresh tanigue soaked in vinegar and spices). He can finish two to three servings of rice and sinigang (sour-stew dish). He would scavenge the cupboard with nuts and dried fruits for snacks. He was not much of a sweet-eater but he loves all flavors of crepe, Nutella, cheese, fresh fruits, ice cream, even the veggies, and meat. I could always count on food to bring him joy, and then one day he just lost interest. He was too lazy to eat and sometimes he would complain of stomach cramps. He will just drink tea and eat a slice of bread just to avoid having an argument with me for not eating. Aside from stomach cramps, he'd feel bloated and nauseous.
4. Muscle Rigidity
My easy-going teenager suddenly became tense. There was awkwardness and rigidity when I hugged him, clung to his arms, or just held his hands. I thought it was just a phase of his teenage years, he will eventually be easy and confident again in himself. But that didn't happen.
He loves music so much. He was excited to get back to his music lesson but later last year he had a hard time moving his fingers to the keyboards and violin so he lost his interest in playing. It was heart-breaking for him because his joy became his greatest frustration. No matter how hard he practiced he could not perfect the piece because his fingers were stiff all the time.
Oftentimes, he would feel tightness in his throat and chest. He'd complained of having chest pain after meals. I took that lightly and advised him it's just heartburn so drink enough water and eat slowly. And when he drank, he would cough and choke as if he'd drowned while drinking water. It was only now I realise those chest pain and choking incidents may have been caused by tension building up inside him.
5. Headaches
Lately, I'm having constant “tension headaches”, which I'd been diagnosed with years ago. This type of head pain may feel like a mild throbbing sensation, around the eyebrows going down to the jawline, neck, and nape. My doctor said it is due to poor posture and long overdue sitting, standing, or lying down in a bad position. This time, I know it is due to depression, all the crying and sadness drained me and made me feel exhausted, and I'd end up with severe headaches.
I remember Enzo used to complain the same thing to me. He would complain of a headache in the morning and at night. He had a very bad dry scalp so I used to massage his head with hair moisturizer or oil. Sometimes, he'd used it as an excuse to have a good head massage. He will request to not stop on his scalp but also to massage his forehead, nape, and shoulders too. After that, he will be in a happy, good mood and his hugs and kisses would feel natural and sweet. But some days, the massage was not enough so he will course to ibuprofen and paracetamol to stop the pain.
When to seek help...
I really don't know, there is no specific symptom that needs immediate medical attention. All symptoms are equally alarming. But if your teens are likely to keep their distressing emotions like sadness, shame, and anger, this may build up negatively to their physical health. Talk to them about your concerns. Open communication will make them feel you care and that you are available for them to provide support. It seems worked perfectly with Enzo at that time. He started singing and irritable moments lessen. He enjoyed going out again. He managed to respond to friendly chats with others too.
Though, if your teen is experiencing any of these physical symptoms for a period of time, see your doctor. Be completely honest with their physical and emotional symptoms, so your doctor can give you the right medical advice and support. Understanding the physical symptoms of depression may help those struggling with poor mental health and their loved ones to spot the signs as early as possible, as well as change the perception of depression as an "all in the mind" attitude.
PS.
I may not be the right person to give you this advice but know that I am sharing my thoughts because I do not want another loving mother to share the same journey I am right now. I want to believe that there is hope... that depression is treatable and there is help available. I was only days away from help, my dear Enzo had finally agreed to seek medical treatment but he didn't make it on his appointment date. His depression swallowed him unnoticeably that day.