From my Zero Years of actual medical study, but a sperg-tier interest in medicine:
First, yeah. She's lorg. She knows this, however she seems to veer towards the field of HAES. So I'll put most of my Very Scientific Observations in terms of things that would be alarming in someone who was, you know, not 50 pounds heavier than a fully grown grizzly bear.
She has mentioned several times that she sleeps with an abundance of pillows. Needing to have a bunch of pillows to sleep is a red flag for cardiovascular and respiratory symptoms. People often do not think of it as a warning sign because to them, they just notice they're "more comfortable" sleeping with extra pillows. However, they don't realize the discomfort is because lying flat is restricting their ability to breathe, or putting undue stress on their heart. All they know is that their 8 pillow setup is more comfy.
Obviously, you can also see how out of breath she gets from pretty insignificant amounts of movement. She pants between bites. She wheezes. She coughs. She seems to have really labored breathing if she's talking for a long period of time and she hasn't edited out the gaps.
Sleep apnea seems extremely likely. Even if she's not a heavy snore-er, she complains of getting little sleep. Being tired. Being lethargic. I don't recall if she complains of headaches a lot, but waking up with headaches is a big red flag for sleep apnea as well. (Cause, you know, the brain is not too fond of going X amount of hours with really infrequent oxygen snacks.)
So, heart issues. Lung issues. My money would be on obesity hypoventilation syndrome. Which also would explain her constant joint pain, fatigue, etc.
And the beetus: Yeah, even if you took away her weight, she's a prime candidate for diabetes concerns. Slowly healing wounds, darkened knuckles, always thirsty (gorl is always sipping on something) , tired, and an out of control appetite. If she's got any sort of vision issues and pisses a lot, she's ticked off most of the big warning signs.
And her mystery leg issues? She's always complained about sore feet, which is... you know, what happens when you're essentially backpacking with 400 lbs of extra human on you. Now the leg pain that seems to be in her muscle? May be a clot, may be a spasm. My money is on referred joint pain from her hips, or a pinched sciatic nerve. While a clot is scary and interesting, some people made a good point that ALR would have frantically googled her symptoms and would probably NOT wait so long to see a doc if she was experiencing clot symptoms.
I'd be willing to bet she's got a decent amount of edema in her legs as well, but I doubt we'll get a video that shows her getting her legs squeezed to see if she's just got kankles or fuck tons of lymph fluid.
To add to all that, these all fuck with sleep. She mentions sleeping few hours, or sleeping all day, or waking up at weird times. If you fuck with your sleep (even just altering the time you wake or go to bed), it REALLY fucks with your mental health. Inhibition gets fucked. Manic/depressive episodes get amplified. Which means binges get worse. Which contributes to the health issues. Which contribute to sleep issues. Which contributes to worsening mental health, which.... Yadda yadda.
TL;DR:
Lungs are fucked. Heart is probably getting fucked. Immune system and circulation is fucked because 'beetus. Circulation is doublefucked because aforementioned lungs being shitty. Joints are fucked because Gravity Is A Thing. Everything is extra fucked because she's also got poor sleeping patterns.
She's getting really close to a point of no return, where the only solution is going to be hospitalization.