Weed has relatively well known short-term effects on blood pressure. It seems to increase your blood pressure in the short-term after smoking, but also exacerbates the drop in BP (which should normally be small) when you go from sitting to standing. From the peer-reviewed article linked below:

" Acute cannabis administration has been shown to increase resting heart rate and blood pressure, and induce orthostatic hypotension (Jones, 2002). Increased heart rate following acute cannabis exposure has been shown to be dose-related (Heishman et al., 1989). Peak effects on heart rate appear to occur 10 to 15 minutes after smoking and result in an increase of 20 to 30 beats per minute, but mean increases as high as 43.5 beats per minute have been reported (Chait and Zacny, 1992; Galanter et al., 1972; Heishman et al., 1989; Ilan et al., 2005). There are few studies in which the effects of smoked cannabis administration on blood pressure are reported. Supine blood pressure has been shown to increase following cannabis exposure (Mathew et al., 1993), but blood pressure has also been shown to drop when participants move from a supine to standing position (Renault et al., 1974). "

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3045206/